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A 57Fe nucleus in the solar core could emit a 14.4-keV monochromatic axion through the M1 transition if a hypothetical elementary particle, axion, exists to solve the strong CP problem. Transition edge sensor (TES) X-ray microcalorimeters can detect such axions very efficiently if they are again converted into photons by a 57Fe absorber. We have designed and produced a dedicated TES array with 57Fe absorbers for the solar axion search. The iron absorber is set next to the TES, keeping a certain distance to reduce the iron-magnetization effect on the spectroscopic performance. A gold thermal transfer strap connects them. A sample pixel irradiated from a 55Fe source detected 698 pulses. In contrast to thermal simulations, we consider that the pulses include either events produced in an iron absorber or gold strap at a fraction dependent on the absorption rate of each material. Furthermore, photons deposited on the iron absorber are detected through the strap as intended. The identification of all events still needs to be completed. However, we successfully operated the TES with the unique design under iron magnetization for the first time., Comment: 10 pages, 6 figures, published in Journal of Low Temperature Physics on 4 February 2023

The defect formation in a rod-shaped AA7003 alloy is carefully treated in the sample extruded at 10 or 20 m min−1 with their structure–property relationships. The + double fibre texture...

Yerba Santa (Eriodictyon angustifolium and Eriodictyon californicum) has been used for many years in traditional medicine. However, the effect of Yerba Santa on melanogenesis has not yet been investigated. We aimed to assess the biological effects of Yerba Santa on hair pigmentation.Yerba Santa extracts were assessed for their cytological effects following X-ray irradiation treatment and then tested directly for the prevention of human hair greying. Ultra-performance liquid chromatography (UPLC) was utilized to identify the individual extract components.Eriodictyon angustifolium extract significantly increased melanin synthesis in the melanoma cell line through activation of the WNT/MITF/tyrosinase-signalling pathway. In contrast, E. californicum had no effect on melanin synthesis. E. angustifolium extract also demonstrated a protective effect against the damage induced by X-ray irradiation in human keratinocytes. Application of the extracts to subjects who had grey beards demonstrated a reduced number of grey beard hair per year specifically with the E. angustifolium extract. A significant decrease in grey head hair was also observed after application of E. angustifolium extract. Upregulation of gene expression related to melanin production and WNT signalling was observed after the application of E. angustifolium extract. Sterubin was the most abundant flavonoid detected by UPLC in E. angustifolium extract. In addition, sterubin showed the highest difference in terms of quantity, between E. angustifolium and E. californicum extract.Eriodictyon angustifolium extract, which is abundant in sterubin, may be suitable as a potential cosmetic and medical agent for the prevention and improvement of hair greying.Yerba Santa (Eriodictyon angustifolium et Eriodictyon californicum) est utilisé depuis de nombreuses années en médecine traditionnelle. Cependant, l'effet de Yerba Santa sur la mélanogenèse n'a pas encore été étudié. Notre objectif était d'évaluer les effets biologiques de Yerba Santa sur la pigmentation des cheveux. MÉTHODES: Les extraits de Yerba Santa ont été évalués pour leurs effets cytologiques après un traitement d'irradiation aux rayons X, puis testés directement pour la prévention du grisonnement des cheveux humains. La chromatographie liquide ultra-performante (UPLC) a été utilisée pour identifier les composants d'extrait individuels. RÉSULTATS: L'extrait d'E. angustifolium a augmenté de manière significative la synthèse de mélanine dans la lignée cellulaire du mélanome par l'activation de la voie de signalisation WNT/MITF/tyrosinase. En revanche, E. californicum n'a eu aucun effet sur la synthèse de mélanine. L'extrait d'E. angustifolium a également démontré un effet protecteur contre les dommages induits par l'irradiation aux rayons X dans les kératinocytes humains. L'application des extraits à des sujets qui avaient une barbe grise a démontré un nombre réduit de poils gris par an spécifiquement avec l'extrait d'E. angustifolium. Une diminution significative des cheveux gris a également été observée après l'application d'extrait d'E. angustifolium. Une régulation à la hausse de l'expression des gènes liée à la production de mélanine et à la signalisation WNT a été observée après l'application d'extrait d'E. angustifolium. La stérubine était le flavonoïde le plus abondant détecté par UPLC dans l'extrait d'E. angustifolium. De plus, la stérubine a montré la plus grande différence en termes de quantité entre E. angustifolium et E. californicum.L'extrait d'E. angustifolium, qui est abondant en stérubine, peut convenir comme agent cosmétique et médical potentiel pour la prévention et l'amélioration du grisonnement des cheveux.

Galvanostatic electrodeposition of Li was carried out in 1 M LiTFSI/PC electrolyte to investigate the effect of current density on the morphological variations during the initial stage of the electrodeposition. The solid electrolyte interphase (SEI) formation process was analyzed from the potential change combined with XPS and UPS measurements along with SEM observation of Li deposits. A significant difference in the deposited Li morphology was observed depending on the current density. The simultaneous growth of whisker-like and granular deposits was noticed at lower current density, while the experiments at higher current densities evolved rather uniform mesoscopic-sized rod development. The formation behavior of SEI prior to Li deposition also differed between lower and higher current densities, of which the transition was about 4 mA cm−2. It was deduced that the formation history of SEI affected the surface defect density heterogeneity and mass transport properties inside SEI. The event of “sprouting,” in which Li precipitates nucleated and grown in SEI are extruded from the SEI layer into the electrolyte, certainly influenced the subsequent growth mode. The diffusion coefficient of Li+ in the SEI galvanostatically formed on Ni substrate in 1 M LiTFSI/PC was estimated to be in the order of 10−9 cm2 s−1.

Li electrodeposition in LiTFSI/PC electrolyte up to 2.22 mAh cm−2 was performed by changing the current density from 0.2 to 60 mA cm−2 under optical microscope observation with a resolution of a few micrometers. The evolution of morphological variation followed by the initial stage (less than 0.028 mAh cm−2 in Part 1) was carefully observed. Two-step linearity was obtained in the relationship between the time variations of apparent electrode diameter and the square root of the duration period. At lower current densities less than 2 mA cm−2, locally and stochastically grown Li deposits with several ten micrometers in length were observed. It grew through SEI layer characterized probably by significant heterogeneous surface chemistry nature. Above 8 mA cm−2, the mass transfer effects on the electrode potential and deposit morphologies became predominant. The movement of suspended particles was occasionally observed. It suggested the induction of natural convection in the organic electrolyte. The limiting current density accompanying Li electrodeposition along a vertical Ni cathode was calculated to be 44 mA cm−2, which was well consistent with the LSV measurement.

Cognition of space and time affect each other; a line with longer length appears to be longer in exposure duration (space on time), and a line with longer exposure duration appears to be longer in length (time on space). This cognitive interaction is known to be asymmetric; the effect of space on time is larger than that of time on space. We conjectured that this asymmetry is not intrinsic but may depend on the saliency of relevant signals. Participants were asked to judge the visual exposure duration of lines that varied in length or the lengths of the lines with different exposure times. The ranges of task-relevant and -irrelevant stimulus values were the same in the spatial and temporal tasks. Task difficulty was also evaluated by subjective rating. We found that duration affected the judgment of length more than vice versa, when the spatial task was significantly more difficult than the temporal task. Together with our previous results that showed the opposite effect, our conjecture is supported that the saliency of stimuli should affect the balance of interactions.

At the Kansai Photon Science Institute of the Japan Atomic Energy Agency, we have developed a Compton backscattered X-ray source in the energy region of a few hundred keV. The X-ray source consists of a 150-MeV electron beam, with a pulse duration of 10 ps (rms), accelerated by a Microtron accelerator and an Nd:YAG laser, with a pulse duration of 10 ns (FWHM). In the first trial experiment, the X-ray flux is estimated to be (2.2±1.0)×10 2 photons/pulse. For the actual application of an X-ray source, it is important to increase the generated X-ray flux as much as possible. Thus, for the purpose of increasing the X-ray flux, we have developed the pulse compression system for the Nd:YAG laser via stimulated Brillouin scattering (SBS). The SBS pulse compression has the great advantages of a high conversion efficiency and a simple structure. In this article, we review the present status of the Compton backscattered X-ray source and describe the SBS pulse compression system.

Synchrotron radiation-induced total reflection X-ray fluorescence (SR-TXRF) analysis is a high sensitive analytical technique that offers limits of detection in the femtogram range for most elements. Besides the analytical aspect, SR-TXRF is mainly used in combination with angle-dependent measurements and/or X-ray absorption near-edge structure (XANES) spectroscopy to gain additional information about the investigated sample. In this article, we briefly discuss the fundamentals of SR-TXRF and follow with several examples of recent research applying the above-mentioned combination of techniques to analytical problems arising from industrial applications and environmental research.

We carried out research in Lake Suwa from 2004 to 2008 to study how retention time affects the biomass and species composition of blue-green algae. The retention time of the lake ranged from 2.3 (rainy season in July 2006) to 120 (dry season in June 2005) days. Microcystis was predominant in summer, but Aphanizomenon was predominant in 2005 and 2006. Owing to nitrogen deficiency, the Microcystis population increase was suppressed when retention time was kept at more than 80 days. The increase in the population of Aphanizomenon flos-aquae was suppressed probably owing to the dilution and discharge of cells by precipitation, and the change of the predominant species caused by nutrient inflow. In this paper, we suggest an appropriate retention time for respective blue-green algae on the basis of changes in the predominant species caused by changes in retention time.

A novel type of submicron ion radiography designed to image low-contrast objects, including nanofoils, membranes and biological structures, is proposed. It is based on femtosecond–laser-driven-cluster- plasma source of multicharged ions and polymer dosimeter film CR-39. The intense isotropic ion flow was produced by femtosecond Ti:Sa laser pulses with intensity ∼ 4x1017 W/cm2 absorbed in the supersonic jet of the mixed He and CO2 gases. Two Focusing Spectrometers with Spatial Resolution (FSSR) were used to measure X-ray spectra of H-and He-like multicharged oxygen ions. The spectra testify that ions with energy more than 300 keV were radiated in different directions from the plasma source. High contrast ion radiography images were obtained for 2000 dpi metal mesh, 1 μm polypropylene and 100 nm Zr foils as well as for the different biological objects. Images were recorded on a 1 mm thick CR-39 detector, placed in contact with back surface of the imaged samples at the distances 140 -160 mm from the ion source. The spatial resolution of the image no worse than 600 nm was provided. A difference in object thickness of 100 nm was very well resolved for both Zr and polymer foils. The ion radiography images recorded at different angles from the source, demonstrated almost uniform spatial distribution of ion with total number of 108 per shot (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

It has been shown that a femtosecond plasma of cluster targets is an almost isotropic source of fast ions and, hence, can be used to obtain ionographic images with a wide field of view. The spatial resolution of the resulting ionographic images is no worse than 600 nm, which corresponds to a uniquely high value of about 105 of the ratio of the field of view to the resolution. The use of 100–300-keV ion fluxes ensures the sensitivity of the method to the sample thickness of no worse than 100 nm even for samples consisting of light chemical elements (C, H). The proposed method can be used to obtain images of low-contrast biological objects, thin films, membranes, and other nanostructured objects.

In 2003 IAEA launched the EMRAS Programme aiming at evaluating the predictive power of radiological models. The programme continued work of previous international radioecological modelling programmes and comprised several working groups focusing on different aspects of environmental modelling. The Iodine Working Group reassessed the impact of the release of 131 I during the Chernobyl accident with the aim of comparing model predictions with environmental data and inter-comparing the model predictions. Measurement data and detailed geographic and demographic descriptions were available for three regions: Plavsk, Warsaw and Prague. As for the Prague Scenario, milk supply regions of three big dairies were chosen for the model validation. Apart from geographic, demographic and agricultural descriptions (e.g. gathering regions of the dairies, feeding regime), the modellers were provided with information on the weather conditions and measurement data of iodine contamination. The most important peculiarities of Prague Scenario were keeping milk cattle in sheds and a special feeding regime during May 1986. The modellers were asked to assess the 131 I content in the thyroid of the local population and the resulting dose. The assessments were compared with measurement data. The results of these model calculations and their comparison with experimental data are presented.

The studies undertaken by the 131I Working Group, part of the International Atomic Energy Agency's EMRAS (Environmental Modelling for Radiation Safety) programme, were focused primarily on evaluating the predictive capability of environmental models. Particular emphasis was placed on applying models to evaluate the effectiveness of countermeasures. © 2008 IAEA.

Purpose: Changes in body composition of college wrestlers undergoing rapid weight reduction were evaluated over time using magnetic resonance imaging (MRI). Methods: We evaluated 12 wrestlers (male, 18–22 years of age) who participated in Japan’s 2005 intercollegiate wrestling tournament. For this study, MRI (of the right femoral region and the trunk), as well as measurements of body weight, body fat percentage and body water content, were performed one month and one week prior to the weigh-in, on the day of the weigh-in, on the day of the match (after the match), and one week after the weigh-in. A survey of food and fluid intake was also conducted. Results: Several variables were significantly lower on the day of the weigh-in than one month prior: body weight (p

We demonstrate a highly reproducible acceleration of a high-quality electron bunch injected into the laser wake field accelerator with the help of a countercrossing laser pulse. In our experiments, the wake field is generated by a subrelativistic laser pulse; the second laser pulse collides with the first pulse at 135 , realizing optical injection of electron bunch into the wake field. Because the second pulse is countercrossing, it cannot damage the laser system. The observed electron bunch has the energy of 14 MeV with an 11% (1.5 MeV) spread, the total charge of 22 pC, and a reproducibility of at least 50%.

Using a cluster jet containing Ar clusters, collimated relativistic electrons up to 58 MeV with an electron charge of 2.1 nC were generated by a laser–cluster interaction. The resulting spectrum does not fit a Maxwellian distribution, but is well described by a two-temperature Maxwellian. Two-dimensional particle-in-cell simulations demonstrate an important role of clusters that the higher energy electrons are injected by the laser pulse interaction with the clusters and then they gain their energy during the direct acceleration by the laser pulse, while the lower energy electrons are accelerated by the wakefield being injected during the plasma wave breaking.

The results of experiments are presented for a single laser pulse interaction with a very low density gas target under conditions when the generated wake wave is below the wave-breaking threshold and the laser pulse power is lower than the critical power for relativistic self-focusing. A quasimonoenergetic electron beam is found to be stably generated for various laser pulse intensity values by controlling the acceleration length.

We present the results of electron generation experiments conducted at the Advanced Photon Research Center, Japan Atomic Energy Research Institute, using 23-fs relativistically intense 20-TW tightly focused laser pulses with underdense plasma. We observed electron energies up to 40 MeV characterized by a two-temperature Maxwell distribution. With the help of particle-in-cell simulations, we found that these are due to different plasma wave-breaking processes. A charge of 5 nC/shot was obtained at a small solid angle, which corresponds to high peak current generation.

Experimental training model of rats with spinal cord injury (SCI).Osaka, JapanObjective:To investigate the effect of forced treadmill training by plantar placement (PP), as compared with dorsal placement (DP), of the dorsal paws on the locomotor behaviors of spinal cord-injured rats.The spinal cord was contusion-injured at the thoracic level. Rats were divided into three groups: forced training involving stepping by PP and DP and non-forced training/assistance (nT). Training began 1 week after injury and was conducted for 4 weeks. Locomotor behaviors were estimated using Basso-Beattie-Bresnahan (BBB) scores, dorsiflexion of the hind paws and footprints of the hind paws. Histological and immunohistochemical examinations of the spinal cord lesions were conducted after 4 weeks of training.The values, respectively, of PP, DP and nT groups at 4 weeks of training were as follows: BBB scores were 15.6±0.8, 7.7±1.3 and 10.3±0.4. The paw dorsiflexion angles were 34.1±5.2, 16.4±2.4 and 23.6±3.0 degrees, respectively. The stride angles were 5.1±0.9, 13.7±4.9 and 17.8±4.0 degrees for the left paws. Cavity volumes were 10.3±2.1, 31.0±2.0 and 28.2±4.9%. In addition to cavities, there were astrocyte-devoid areas containing some loose tissues, through which many axons extended longitudinally.The BBB score, dorsiflexion angle and stride angle were consistently improved in the PP group. Cavity formation was more reduced, and many axons extended through coarse tissues formed in astrocyte-devoid areas at the lesion in the PP group. Forced training by PP of the hind paws promoted the behavioral and histological improvement of rats with SCI.

The interaction of space and time affects perception of extents: (1) the longer the exposure duration, the longer the line length is perceived and vice versa; (2) the shorter the line length is, the shorter the exposure duration is perceived. Previous studies have shown that space-time interactions in human vision are asymmetrical; spatial cognition has a larger effect on temporal cognition rather than vice versa (Merritt et al., 2010). What makes the interactions asymmetrical? In this study, participants were asked to judge exposure duration of lines that differed in length or to judge the lengths of the lines with different exposure time; to judge the task-relevant stimulus extents that also varied in the task-irrelevant stimulus extents. Paired spatial and temporal tasks in which the ranges of task-relevant and -irrelevant stimulus values were common, were conducted. In our hypothesis, the imbalance in saliency of spatial and temporal information would cause asymmetrical space-time interaction. To assess the saliency, task difficulty was rated. If saliency of relevant stimuli is high, the difficulty of discrimination task would be low, and vice versa. The saliency of irrelevant stimuli in one task would be reflected in the difficulty of the other task, in the pair of tasks. If saliency of irrelevant stimuli is high, the difficulty of paired task would be low, and vice versa. The result supports our hypothesis; spatial cognition asymmetrically affected on temporal cognition when the difficulty of temporal task was significantly higher than that of spatial task.

Optical properties of fluorinated silicon oxide (SiOF) films for optical waveguide in optoelectronic devices were investigated. The SiOF films are formed at 25/spl deg/C by a liquid phase deposition (LPD) technique using a supersaturated hydrofluosilicic acid (H/sub 2/SiF/sub 6/) aqueous solution. Two main absorption peaks corresponding to Si-O and Si-F bonds were observed at the wavenumbers of 1090 and 930 cm/sup -1/ in Fourier transform infrared (FTIR) spectrum, respectively. The LPD-SiOF films show very little content of water components such as Si-OH bonds and OH group. Although the transmittance for 600-nm-thick LPD-SiOF film gradually decreased from the wavelength around 700 nm, the relative transmittances to quartz glass are over 98% in the wavelength region from 350-2500 nm. The concentration of fluorine atoms in the LPD-SiOF film was about 5%, and the calculated composition was SiO/sub 1.85/F/sub 0.15/. The calculated refractive index from the polarizability for LPD-SiOF film was 1.430, and agrees very well with the measured value at the wavelength of 632.8 nm by ellipsometry. The dispersion of refractive index was evaluated and fitted to a three-term Sellmeier's dispersion equation. The zero dispersion wavelengths for the LPD-SiOF and thermally grown SiO/sub 2/ films were 1.271 and 1.339 /spl mu/m, respectively.

The process of oxygen concentration in water was examined in the presence of a magnetic field. The equilibrium concentration of oxygen was found to remain the same whether the field was present or absent, in accordance with the prediction of the laws of thermodynamics. However, it was found that the rate of oxygen dissolution in water was significantly enhanced in a magnetic field. The degree of enhancement of the dissolution rate depended on the magnetic force (x/μ0)·B· (dB/dx) showing a minimum at the position in which the magnetic field was strongest. The phenomenon was explained by assuming that liquid-phase convection is caused by the gradient distribution of dissolved oxygen in water, which in turn raises the gradient of the magnetic susceptibility in a direction perpendicular to the magnetic field gradient.

The magnetic field effect on the formation of a water droplet was investigated by measuring the volume of water droplets formed in a magnet with a vertical field distribution. The maximum field was 9 T at the center of the magnet bore. The droplet volume increased significantly on the upper side of the magnet with a strong field gradient and decreased at the lower side. Measurements were also carried out for several diamagnetic and paramagnetic aqueous liquids, and showed that the same effect was introduced by the presence of a magnetic force. The results agreed with those of calculation. We also succeeded in controlling the droplet volume under a magnetic field of below 1 T by forming a droplet of a liquid in another liquid of similar density.

Dispersion of diamond in metal matrices is expected to improve friction and wear properties. In this paper, cluster diamonds (average grain size: 5nm) are dispersed in pure copper matrix by a P/M method. A mechanical milling method is employed for the composite powder mixing. First, the change in morphology after milling and sintering is observed by SEM. Next, the influence of milling time and cluster diamond content on the friction coefficient and the specific wear rate of the composite are examined. The friction coefficient measured by a ring-on-disk method decreases with the increase in both milling time and diamond content. About 30% reduction of friction coefficient compared with the pure copper is achieved for the composite (diamond content: 1vol%) after a milling time of 40 hours. The specific wear rate also decreases with the milling time. However, the rate increases significantly as the diamond content increases. The experimental results show the possibility of a solid lubricant of diamond-dispersed metal matrix composites.

Study design This is a case report. Objective To focus attention on a possible neurologic complication of laminoplasty. Summary of background data An iatrogenic spinal cord lesion developed after laminoplasty as an operative complication of unknown cause. Methods Two patients had iatrogenic damage to the spinal cord from an unknown cause after laminoplasty of the cervical spine, but recovered soon after an additional laminectomy. They were evaluated with regard to the mechanism of damage and prevention. Results The spinal cord damage occurred when the spinal cord migrated posteriorly and deformed between the split laminae at the apex of the lordosis, where the maximum posterior displacement of the spinal cord was achieved. Conclusion This damage was caused by a relatively narrower canal resulting from the split laminae of the apex of the adjacent laminae.

Nutrient-induced thermogenesis (NIT) induced by parenteral infusion of amino acid (AA) mixtures of different composition and of the same AA mixtures given via different routes (parenteral or intraportal infusion) were investigated in rats using a small animal indirect calorimeter. When 8 different AA solutions of differing composition but with the same total concentration were infused parenterally, both standard NIT (each AA is assumed to generate 3.28 kcal/g) and specific NIT (heat energy of each AA is calculated assuming that it is oxidized to carbon dioxide and water, and metabolised to urea and sulphuric acid) values of the leucine (Leu)-rich and the glycine (Gly)-rich solutions were significantly greater than those of the control solution. Removal of Leu or Gly from the respective AA solutions reversed the increase of both NIT values down to control levels. When the parenteral and portal infusion routes were used in one rat, both NIT values for parenteral infusion of the Leu-rich solution were again significantly greater than those of the control. Likewise, both NIT values for intrportal infusion of the Leu-rich solution were also significantly greater than those of the control. However, no difference in NIT values was found between parenteral and portal infusion of either solution. The result of this study indicated that Leu and Gly may be thermogenic AAs, and the thermogenic effect of Leu is not dependent upon the route of infusion.

Cisplatin (cis-dichlorodiammineplatinum II, CDDP) is one of the most important anti-cancer drugs for gastroesophageal cancers, but its nephrotoxicity is a dose-limiting side effect which hinders clinical application. In this study, two kinds of newly devised infusion resimens were tested for the prevention potential of the nephrotoxicity of CDDP. The subjects were 24 patients with esophageal or gastric cancer treating with anti-cancer drugs including CDDP. Sixteen patients (group A) in the former period of this study received massive fluid load (4000 ml/day, Na 245 mEq/day) with diuretics; and 8 patients (group B) in the later period received Na-rich solution (4000 ml/day, Na 346 mEq/day) with plasma expander and sustained infusion of dopamine at 3 μg/kg/min. In group A, nephrotoxicity higher than grade 2 occurred in 37.5% and hyponatremia less than 130 mEq/1 in 44%; versus 12.5% and null in group B, respectively. Moreover remarkable improvement of glomerular function was observed in group B. It is concluded that hydration regimen with plasma expander and dopamine administration in group B appears superior to the other to reduce the nephrotoxicity of CDDP.

Chaotic oscillation of a domain wall is demonstrated by computer simulations based on a differential equation which includes terms for the nonlinear force of restitution and eddy current damping. Chaotic oscillation involves irregular phenomena (the error or noise in magnetic recording systems) and energy losses. Bifurcation diagrams of magnetic domain-wall motion is a useful method for investigating chaotic behavior. The external magnetic field is an important parameter in the design of magnetic devices. The bifurcation diagram of the wall velocity is calculated for the amplitude of the external magnetic field. The route to chaos is through bifurcation via periods 2, 3, 4 and 5 from period-1 oscillation. The periodic windows and chaotic regions appear in alternation. The energy loss caused by the domain wall motion was calculated; the value of the energy loss in chaotic motion is larger than that for regular motion, despite their having the same damping coefficient. Chaotic motion is thus a new mechanism causing increases in the energy loss.

The effects of a competitive neutrophil elastase (NE) inhibitor, ONO-5046, and a recombinant human superoxide dismutase on leukotriene B4 (LTB4)-induced polymorphonuclear leukocyte (PMN)-mediated increase in microvascular permeability in isolated non-blood-perfused rabbit lungs were studied. Pulmonary microvascular permeability and lung edema were evaluated by use of the fluid filtration coefficient (Kf) and the wet-to-dry lung weight ratio (W/D), respectively. Pulmonary capillary pressure was estimated by the double occlusion technique. NE activity in the perfusate was determined using a spectrophotometric method. The PMNs (2–3 x 10(8) cells) were added into the perfusate in all groups of lungs. Injection of LTB4 (5 micrograms) increased Kf and W/D without affecting pulmonary arterial or capillary pressure. The LTB4-induced lung injury was closely associated with the increase in NE activity in the perfusate. Infusion of ONO-5046 (1 or 10 mg.kg-1 x h-1) inhibited the LTB4-induced increases in Kf, W/D, and perfusate NE activity in a dose-dependent fashion. Infusion of recombinant human superoxide dismutase (80,000 U.kg-1 x h-1) attenuated the LTB4-induced increases in Kf and W/D, although it did not influence the elevation of perfusate NE activity induced by LTB4. These results suggest that both NE and superoxide anion play important roles in the LTB4-induced PMN-mediated increase in pulmonary microvascular permeability.