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In the present study, we explored whether sirtuin-3 (SIRT3) regulates the proliferation and migration of esophageal squamous cell carcinoma (ESCC) and investigated the mechanisms underlying the oncogene role of SIRT3. siRNA was used to transfect Eca109 cells and downregulate SIRT3. The proliferation and migration of Eca109 cells were examined by the CCK-8 assay, colony formation assay, Transwell assay, and scratch test. Quantitative real-time PCR and Western blotting were used to detect SIRT3, hexokinase 2, AKT, and p-AKT in Eca109 cells. Functional assays showed that downregulation of SIRT3 could inhibit the proliferation and migration of ESCC cells. Reduced SIRT3 expression downregulated hexokinase 2 expression and inhibited AKT activation in ESCC. These results indicated that SIRT3 promote ESCC development and progression by regulating hexokinase 2 through the AKT signaling pathway. SIRT3 promote ESCC proliferation and migration by regulating HK-2 through the AKT signaling pathway.

This study aimed to evaluate the expression characteristics of lamin A/C proteins in intervertebral disc degeneration (IVD) specimens from patients with different degeneration grades. Lamin A/C proteins have been shown to result in age-related changes in the osteoarticular system. However, the expression characteristics of these nuclear proteins in degenerated human IVD tissues have not been explored previously.Degenerated human IVD tissues were obtained during spinal surgery. Articular cartilage samples after total knee replacement surgery were used as controls. Sections of these tissues were stained with hematoxylin and eosin, Masson, safranin O, and immunostained using lamin A/C antibody. Western blot was performed to evaluate lamin A/C expression in IVD tissues. Lamin A/C expression was analyzed based on different degeneration grades.In patients with IVD degeneration, mild or moderate degenerative discs contained high amounts of lamin A/C proteins. Lamin A/C expression was primarily localized in the nuclear envelope of IVD cells, and associated with apoptosis in cell nuclei, as determined by immunostaining and TUNEL assay.This paper is the first to report that lamin A/C proteins are present in IVD tissues and its expression may be related to disc degeneration.

Objectives: We explored the efficacy of minimal invasive surgery including one-stage debridement and intervertebral fusion through extreme lateral channel (XLIF) combined with lateral or percutaneous posterior pedicle screw fixation for the treatment of lumbar spine tuberculosis. Methods: Twenty two patients with lumbar tuberculosis who underwent surgery with XLIF technique and internal fixation were included in the study. Their data about operative time, intraoperative blood loss, bone fusion, kyphosis correction, and clinical recovery were retrospectively collected and analyzed. Results: The mean intraoperative blood loss was 249.8±27.8 ml and the operative time 347.5±20.7 min. At the final follow-up, 11 to 15 months postoperatively, ESR and CRP were normal and pain (VAS) and Oswestry disability index (ODI) were significantly reduced (23.0±-3.1 vs 0.6±-0.7 and 57.2±-1.6 vs 6.4±-1.2 respectively) compared to preoperative values. Progression of the kyphotic deformity was effectively prevented (mean Cobb angle 23.9° +/-1.9° vs 24.5° +/-1.4°, P>0.05). There was one failure of the fixation associated to poor therapy adherence. All the patients showed neurological recovery. Conclusion: Debridement and interbody fusion by extreme lateral channel combined with lateral or percutaneous posterior pedicle screw fixation effectively retained the spine stability and provided clinical and neurologic recovery in selected patients with lumbar spine tuberculosis.

In this work, we address the issue of spin relaxation and its relevance to spin detection in ZnO-based materials, by spin-polarized, time-resolved magneto-optical spectroscopy. We have found that spin relaxation is very fast, i.e. about 100 ps for donor bound excitons in wurtzite ZnO, despite of a weak spin–orbit interaction. We also reveal that alloying of ZnO with Cd enhances spin relaxation, prohibiting ZnCdO/ZnO structures for efficient optical spin detection. On the other hand, a variation in strain field induced by lattice mismatch with substrates does not seem to lead to a noticeable change in spin relaxation. The observed fast spin relaxation, together with the limitation imposed by the band structure, are thus identified as the two most important factors that limit the efficiency of optical spin detection in the studied ZnO-based materials.

Amorphous Al2O3 thin films were deposited on a Si (1 1 1) substrate at 150 °C in oxygen-rich conditions by atomic layer deposition. Rapid thermal annealing was performed at high temperatures, ranging from 1000 to 1200 °C, to study the crystallization characteristics of the Al2O3 films. X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy, atomic force microscopy and frequency-dependent capacitance measurements were used to characterize the structural and electrical properties before and after the annealing. It was found that the best crystallization of the Al2O3 film was achieved after annealing at 1150 °C, corresponding to a minimum of full width at half maximum (FWHM) of the Al2O3 (012) XRD peak and the maximum of surface roughness and the capacitances. This suggests that 1150 °C is the optimal transition temperature from amorphous to crystalline and to get the best insulating property for Al2O3 thin film. The formation of the SiO2 interfacial layer after annealing has been observed by HRTEM for the annealed sample, accompanied by a decrease in the thickness of Al2O3 films.

We have carried out comprehensive optical studies to evaluate structural and bandgap properties of Zn1-xCdxO alloys with x {less than or equal to} 0.17 grown by molecular beam epitaxy. High crystalline quality of the alloys was concluded from cathodoluminescence measurements. Based on absorption and reflectance measurements, the compositional dependence of the bandgap energy of ZnCdO, estimated without taking into account excitonic effects, was found to follow the trend Eg(x)=3.28- 2.23x+0.45x2. Degradation in the alloy quality due to possible phase separation was found to cause deviations from this trend, evident from a more rapid red shift of the absorption edge. Effects of Cd incorporation on the variation of the bandgap energies with temperature are also discussed.

In the paper we present band-gap alignment diagrams for type-II/type-I heterostructures incorporating the strong piezoelectric and spontaneous polarization fields in ZnCdMgO and AlGaN-based materials and interfaces. The paper describes some of the recent progress made in the development of high quality ZnCdO layers and CdZnO/ZnO heterostructures grown epitaxially by RF-plasma molecular beam epitaxy (MBE). We summarize optical and electrical properties of high quality CdxZn1-xO alloys with Cd mole fraction from 0.02 to 0.78 and discuss phase separation phenomenon, which may be present in ternary alloys. A single-crystal wurtzite structure of CdZnO alloys has been confirmed. We achieved a strong optical emission at RT in the 380 nm to 574 nm spectral range from CdxZn1-xO with various compositions. Dependence of the fundamental optical band gap on the composition of CdxZn1- xO alloys, band gap bowing, and the possible effect of composition micro-fluctuations in ternary CdxZn1-xO alloys on the optical bandgap is also discussed. Time resolved photoluminescence shows multi-exponential decay with 21 psec. and 49{plus minus}3 psec. lifetimes, suggesting that composition micro- fluctuations may be present in Cd0.16Zn0.84O film. We also report on crystallographic and optical properties of CdZnO/ZnO multiple quantum wells.

To create efficient ZnO-based LEDs, it is important to develop practical etching process and optimize Ohmic contacts on ZnO. Wet etch rates at 25{degree sign}C for Zn0.95Cd0.05O grown on sapphire substrates by rf plasma-assisted molecular beam epitaxy were in the range 30-90 nm min-1 using HCl/H2O and H3PO4/H2O (2x10- 3-3.5x10-3 M) solutions. A comparison of Ti/Al/Pt/Au and Ti/Au Ohmic contacts on n-type Zn0.95Cd0.05O layers grown on ZnO buffer layers with GaN/sapphire templates shows a minimum contact resistivity of 2.3x10-4 Ω-cm2 obtained at 500{degree sign}C for Ti/Al/Pt/Au and 1.6x10-4 Ω-cm2 was obtained at 450{degree sign} C for Ti/Au. Ti/Au Ohmic contacts on heavily Al-doped (n~1019 cm-3) n-ZnO produce a low specific contact resistivity of 2.4x10-7 Ω- cm2 in the as-deposited condition and extremely low minimum values of 6x10-8 Ω-cm2 after annealing at 300{degree sign}C.

We report on the fabrication and characterization of an ultraviolet (UV) light-emitting diode (LED) based on a p-n junction MgZnO/ZnO/AlGaN/GaN semiconductor triple-heterostructure (THS). Radio-frequency (RF) plasma-assisted molecular-beam epitaxy (MBE) has been employed to grow individual epitaxial layers of ZnO, MgxZn1−xO, and the complete heterostructure on c-plane GaN/sapphire templates. Various growth strategies have been used to optimize the quality of the ZnO layers as well as to precisely control the composition of the MgxZn1−xO compound. Cross-sectional transmission electron microscopy (TEM) study shows the excellent crystalline quality of the pseudomorphically grown ZnO active region of the device. A strong electroluminescence (EL) emission associated with ZnO excitonic transition was observed up to 650 K. The results shown in this paper strongly suggest the viability of RF plasma-assisted MBE in the development of next-generation UV emitters using ZnO-based materials.

We report the growth of self-assembled ErAs islands embedded in GaAs by molecular beam epitaxy. The nucleation of ErAs on GaAs occurs in an island growth mode leading to spontaneous formation of nanometer-sized islands. Several layers of ErAs islands separated by GaAs can be stacked on top of each other to form a superlattice. X-ray diffraction shows superlattice fringes from such samples. Pump–probe measurements indicate carrier capture times as short as 120 fs. These capture times are strongly correlated with the period of the superlattice.

This paper reviews of some of the progress made in the development of ZnO-based light emitting diodes (LEDs). n-ZnO/p-AlGaN-based heterostructures have been successfully for the fabrication of UV emitting LEDs that have operated at temperatures up to 650K, suggesting an excitonic origin for the optical transitions. RF-plasma-assisted molecular beam epitaxy has been used to grow epitaxial CdxZn1-xO films on GaN/sapphire structure. These films have a single-crystal wurtzite structure as demonstrated by structural and compositional analysis. High quality CdxZn1-xO films were grown with up to x=0.78 mole fraction as determined by RBS and SIMS techniques. Optical emission ranging from purple (Cd0.05Zn0.95O) to yellow (Cd0.29Zn0.71O) was observed. Compositional fluctuations in a Cd0.16Zn0.84O films were not detected by spatially resolved CL measurements, although intensity fluctuation with features of ∼0.5 μm diameter were seen on the intensity maps. Time resolved photoluminescence shows multi-exponential decay with 21 psec. and 49±3 psec. lifetimes, suggesting that composition micro-fluctuations may be present in Cd0.16Zn0.84O film.

ZnO thin films have been epitaxially grown on r-plane sapphire by RF-plasma-assisted molecular beam epitaxy. X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies indicate that the epitaxial relationship between ZnO and r-plane sapphire is (1120)ZnO // (1102)sapphire and [0001]ZnO // [1101]sapphire. Atomic force microscopy measurements reveal islands extended along the sapphire [1101] direction. XRD omega rocking curves for the ZnO (1120) reflection measured either parallel or perpendicular to the island direction suggest the defect density anisotropy along these directions. Due to the small lattice mismatch along the ZnO [0001] direction, few misfit dislocations were observed at the ZnO/Al2O3 interface in the high-resolution cross-sectional TEM image with the zone axis along the ZnO [1100] direction.

We report on p-type AlGaN/GaN and GaN/InGaN superlattice (SL) designs with significantly improved vertical and lateral electrical conductivity (σV and σL). Composition-graded p–AlGaN layers were used to produce eight fold reduction in barrier height and a ∼40% increase in the sheet hole density in the p-GaN wells compared to typical SL structures. Thirteen orders of magnitude and 35 times improvement is obtained for σV and σL compared to typical SL and bulk p-GaN, respectively. A similar approach for p-GaN/InGaN SL resulted in seven fold reduction in barrier height and a ∼30% increase in the sheet hole density in the p-InGaN wells compared to a typical SL structures. σL is strongly dependent on hole mobility in the well and about 19 times improvement is obtained for the optimized design, SL-B, with μp=30 cm2 V-1s-1 compared to bulk-InGaN. More than 10 orders of magnitude improvement in σV is obtained for SL-B compared to modulation doped SL.

Objective. Through the observations of dynamic changes of eNOSmRNA and iNOSmRNA in arterial endothelial cells of systematic circulation and pulmonary circulation under simulated weightlessness, to collect some data for studies of the adaptive mechanisms of local regulation in arterial systems. Method. Wistar rats were -30 degrees tail suspended to simulate the effects of weightlessness. The rats were randomly divided into three groups: control group (CON), 7-day tail suspension group (TS7) and 14-day tail suspension group (TS14). Changes of NOSmRNA expresses in endothelial cells of the thoracic aortae and pulmonary arteries were observed with in situ hybridization technique. Result. The eNOSmRNA and iNOSmRNA of thoracic aortic and pulmonary arterial endothelial cells in TS7 rats increased very significantly. The eNOSmRNA of thoracic aortic endothelial cells from TS14 rats returned to control level, but remained very significantly increased in pulmonary arteries. The iNOSmRNA in pulmonary arterial endothelial cells from TS14 rats decreased very significantly, but that in thoracic aortae returned to the control level. Conclusion. The responses of eNOSmRNA and iNOSmRNA in arterial endothelial cells of systematic circulation to tail suspension were similar, but they were different in pulmonary arterial endothelial cells, which might be due to the difference in the peak course of the shift of fluid from lower body entering the pulmonary or systematic circulation during initial period of simulated weightlessness. It could be a kind of important sign of depressed local regulative function under simulated weightlessness and might contribute to orthostatic intolerance after simulated weightlessness.

In the present study, the effects of lycium barbarum polysaccharide (LBP) on endothelial function in the two-kidney, one clip model of hypertension were observed. The results showed that the increase of blood pressure in hypertension rats (HR) could be prevented significantly by treatment with 10% LBP. In isolated aortic rings of LBP-treated rats, the contraction of phenylephrine (PE) was reduced as compared with HR rats. Removal of the endothelium abolished the difference of PE-induced vasoconstriction among groups. In vitro incubation of aortic rings from LBP-treated rats with methyl blue (MB) or N-nitro-L-arginine methyl ester (L-NAME) increased the magnitude of PE-induced contraction. Meanwhile the response to acetylcholine (ACh) was significantly increased in LBP-treated rats, but the response to nitroprusside had no significant difference among groups. Pretreatment with L-arginine partially restored ACh-induced relaxation in RH rats, but no effect in LBP-treated rats. These results suggested that the role of LBP in decreasing vasoconstriction to PE may be mediated by increase of the effects or/and production of endothelium-derived relaxation factor (EDRF). LBP increased formation of EDRF may be related to increase the substrate of EDRF.

Short term hypoxia induced endothelial cells (ECs) injury, as manifested in increasing lactate dehydrogenase (LDH) release and malondialdehyde (MDA) content, decreasing nitric oxide (NO) production and antioxidant enzyme glutathione peroxidase (GSH-Px) activity and increased intracellular calcium concentration, which were further exaggerated by reoxygenation. Administration of 200 U/ml superoxide dismutase (SOD) before hypoxia could partially prevent EC from such injuries, suggesting that the presence of oxygen free radicals may be one of the main factors involved in hypoxia-reoxygenation injury. The ameliorative effect of SOD in case is obviously due to elimination of oxygen free radicals.

A whispering gallery mode optical resonator has been achieved using individual ZnO micro- and nanocolumns. Monochromatic cathodoluminescence images of the ZnO micro- and nanocolumns show that enhanced luminescence intensity is located across the profile of the micro- and nanocolumns, and is mainly attributed to the whispering gallery mode (WGM) enhanced emission. The individual hexagonal ZnO micro- and nanocolumns are regarded as an optical resonator structure. Theoretical calculations and computer simulations based on the finite-difference time-domain suggest that the WGMs are generated in the ZnO micro- and nanocolumns, and these results agree closely with the experimental results.

Field experiments on integrated control of pests injuring Chinese hawthorn by some nonpollution techniques including agricultural biological and physical methods, were carried out in Xinglong County, Hebei Province during 1989-1991. Satisfactory results were obtained. Compared with synthetic pesticides, the new techniques improve the control effect by 30%-60% generally, increase the number of natural enemies by 51.26%-68.51%, and enhance the yield by 47.58%. The test shows that the hawthorns from the field treated by the new techniques are either free of pesticide residual or with a residual 500-1000 times less than the residual standard fixed by FAO/WHO or the state.

Temperature-dependent cw- and time-resolved photoluminescence (PL), as well as optically detected magnetic resonance (ODMR) measurements are employed to evaluate effects of deuterium (2H) doping on optical properties of ZnCdO∕ZnO quantum well structures grown by molecular beam epitaxy. It is shown that incorporation of H2 from a remote plasma causes a substantial improvement in radiative efficiency of the investigated structures. Based on transient PL measurements, the observed improvements are attributed to efficient passivation by hydrogen of competing nonradiative recombination centers via defects. This conclusion is confirmed from the ODMR studies.

Two dominant factors limiting efficiency of optical spin detection in ZnO-based materials system are identified from time-resolved optical orientation and magneto-optical studies. The first is related to the fundamental band structure of the materials characterized by a weak spin-orbit interaction. It leads to cancellation of circular polarization from the optical transitions between the conduction band and the A and B valence band states, which would otherwise carry the desired information on spin polarization of carriers. The second limiting factor is shown to be efficient carrier/exciton spin relaxation, i.e., about 45–80ps.

ZnO∕ZnCdO∕ZnO multiple quantum well samples grown on sapphire substrates by molecular beam epitaxy and annealed in situ were exposed to D2 plasmas at 150°C. The deuterium showed migration depths of ∼0.8μm for 30min plasma exposures, with accumulation of H2 in the ZnCdO wells. The photoluminescence (PL) intensity from the samples was increased by factors of 5 at 5K and ∼20 at 300K as a result of the deuteration, most likely due to passivation of competing nonradiative centers. Annealing up to 300°C led to increased migration of H2 toward the substrate but no loss of deuterium from the sample and little change in the PL intensity. The initial PL intensities were restored by annealing at ⩾400°C as H2 was evolved from the sample (∼90% loss by 500°C). By contrast, samples without in situ annealing showed a decrease in PL intensity with deuteration. This suggests that even moderate annealing temperatures lead to degradation of ZnCdO quantum wells.

Temperature dependent cw- and time-resolved photoluminescence combined with absorption measurements are employed to evaluate the origin of radiative recombination in ZnCdO alloys grown by molecular-beam epitaxy. The near-band-edge emission is attributed to recombination of excitons localized within band tail states likely caused by nonuniformity in Cd distribution. Energy transfer between the tail states is argued to occur via tunneling of localized excitons. The transfer is shown to be facilitated by increasing Cd content due to a reduction of the exciton binding energy and, therefore, an increase of the exciton Bohr radius in the alloys with a high Cd content. © 2007 American Institute of Physics.

Current transport mechanisms and persistent photoconductivity effects were studied in nitrogen-doped ZnO films grown by molecular beam epitaxy having p-type or n-type conductivity at 25°C. In both types of samples the current flow is determined by the n-type channels surrounded by higher resistivity regions. The persistent photoconductivity wave form is reasonably described by the stretched-exponents-type expression, with only a slight temperature dependence of the characteristic decay time. The persistent photocurrent decay process is greatly accelerated by infrared illumination (threshold energy of the photons ∼1.4eV). The results suggest that the Fermi level in the higher resistivity regions is pinned near Ev+1.9±0.1eV and the height of the potential barrier for electrons in the n-type channels is around 1.4±0.1eV.

Optical absorption and reflectance measurements are performed to evaluate compositional and temperature dependences of band gap energies of Zn1−xCdxO alloys grown by molecular-beam epitaxy. The compositional dependence of the band gap energy, determined by taking into account excitonic contributions, is shown to follow the trend Eg(x) = 3.37−2.82x+0.95x2. Incorporation of Cd was also shown to somewhat slow down thermal variation of the band gap energies, beneficial for future device applications.

n-type ZnMnO spin injection layers were grown by pulsed laser deposition on top ofn-ZnMgO∕ZnO∕p-AlGaN∕p-GaN hybrid spin light-emitting diode (LED) structures synthesized by molecular-beam epitaxy. Both the ZnMnO∕ZnMgO∕ZnO∕AlGaN∕GaN structures and control ZnMnO samples show no or very low (up to 10% at the lowest temperatures) optical (spin) polarization at zero field or 5T, respectively. This indicates difficulties in generating spin polarization by optical spin orientation or possible efficient spin losses. The results are similar to those found earlier for GaMnN∕InGaN∕AlGaN spin-LED structures and indicate that these wide-band-gap dilute magnetic semiconductors with weak spin-orbit interaction and hexagonal symmetry are not attractive for spin-LED applications.

X-ray photoelectron spectroscopy was used to measure the energy discontinuity in the valence band (ΔEv) of Zn0.95Cd0.05O∕ZnO heterostructures grown by rf plasma-enhanced molecular-beam epitaxy. A value of ΔEv=0.17±0.03eV was obtained by using the Zn 2p energy level as a reference. Given the experimental band gap of 2.9 eV for the Zn0.95Cd0.05O, this would indicate a conduction band offset ΔEC of 0.30 eV in this system.

We report on the fabrication of UV light-emitting diodes (LEDs) based on a p–n junction n-ZnMgO/n-ZnO/ p-AlGaN/ p-GaN semiconductor triple-heterostructure. Radio-frequency plasma-assisted molecular beam epitaxy was used to grow the complete heterostructure on p-AlGaN/ p-GaN c-plane sapphire templates. Cross-sectional transmission electron microscopy showed single-crystal quality of the pseudomorphically grown ZnO active region of the device. The LEDs were fabricated by a process involving both wet and dry etching. Electroluminescence emission most likely associated with ZnO excitonic transition was observed up to 370°C. The results show the potential of ZnO-based materials for UV emitters of potentially lower cost and with comparable or higher emission intensity than comparable AlGaN/GaN devices.

Two different types of ZnO-based light-emitting diode structures have been examined using a one-dimensional (1D) simulator that accounts for specific features of the hexagonal semiconductors—strong piezoeffects, existence of spontaneous electric polarization, low efficiency of acceptor activation, and high threading dislocation density (normally, ∼107–109cm−2) in the material. A hybrid ZnO∕CdZnO∕AlGaN∕GaN structure grown on sapphire avoids problems in achieving robust p-type doping in ZnO. An all-ZnO approach employs a MgZnO∕CdZnO∕MgZnO double heterostructure grown on a ZnO substrate. Both structures show a strong sensitivity of emission intensity to doping and layer thicknesses within our simulations.

Ferromagnetic bcc-FexCo1−x(100) films have been successfully grown on GaAs(100) and ScyEr1−yAs(100) by molecular beam epitaxy. X-ray diffraction combined with reflection high energy electron diffraction and low energy electron diffraction patterns revealed the epitaxial orientation of bcc-FexCo1−x(100)〈010〉‖GaAs(100)〈010〉 and bcc-FexCo1−x(100) 〈010〉‖ScyEr1−yAs(100)〈010〉. Rutherford backscattering channeling minimum yields, χmin∼3%, suggest epitaxial films of high crystalline quality. Vibrating sample magnetometry measurements show in-plane uniaxial anisotropy and fourfold in-plane anisotropy for FexCo1−x grown on GaAs(100) and ScyEr1−yAs(100), respectively. The difference in magnetic anisotropy is interpreted as arising from the ScyEr1−yAs interlayer altering the surface symmetry from twofold symmetry for GaAs(100) to fourfold symmetry. Misoriented substrates were also used to increase the step density in the [011] direction, which induced an additional uniaxial anisotropy with a [011] easy axis and a [01...

The potential mechanism of fluorocarbon emulsion (FCE)-induced anaphylactoid reactions characterized by transient flush and respiratory disturbance in a few patients were elucidated by detecting the immunological response and the blood vessel vasoactive amine content. The passive cutaneous anaphylaxis (PCA) test in rats immunized with FCE was negative. The precipitating FCE reaction antibody (FRA) in sera of rabbits at 20 min and 24 h after i.v. infusion of FCE 10 ml/kg by reversible single radioactive immunodiffusion (RSRI) was positive, the densities of FRA were negatively related to the dilution of FCE (24 h, r = -0.9998). Histamine and 5-hydroxytryptamine (5-HT) content in peripheral blood of rabbits using fluorochromatography were decreased by 79% and 92% respectively at 10 min after i.v. infusion of FCE 10 ml/kg. Platelet counts fell to 67%, WBC to 47% and the ratio of polymorphonuclear cells and lymphocytes (P/L) was depressed by as much as half of that before infusion. Small arterioles of lungs were filled with macrophages. These results indicated that the mechanisms of FCE-induced anaphylactoid reactions did not involve IgE-dependent mediator release (histamine and 5-HT), but was associated with FCE-FRA complex formation and macrophage-stasis in pulmonary vessels.

EDTA-fluorocarbon microspheres (EDTAFM), calcium disodium ethylene diaminetetraacetate (CaNa2EDTA), calcium- or zinc-diethylene triamine pentaacetate (Ca- or Zn-DTPA) were investigated for their ability to treat experimental lead intoxication in mice. The 48 ICR mice were divided into six groups. Group I = no treatment; The other groups were injected with single ip doses of 210Pb (10 mg Pb2+ +555 kBq/kg). After 24 h they were injected in the tail vein with the chelating agents (20 mg/kg) or an equal volume of 10% glucose (10 mg/kg). Each mouse was housed in one metabolic cage, and urine was collected daily for 3 d. After 3 d, the mice were sacrificed for comparison of lead distribution within the liver, kidney, femur and the entire carcass as measured by 0.047 Mev gamma emission from 210Pb. The results reveal that injection of EDTA-FM to lead poisoned mice pretreated with 210Pb was more effective than Zn- or Ca-DTPA and CaNa2EDTA in reducing the lead induced inhibition in the activity of blood ALAD, and that it increased the excretion of 210Pb into the urine. The hepatic, renal and femur 210Pb contents after treatment with EDTAFM were much more decreased than Zn- or Ca-DTPA and CaNa2-EDTA. The order of effectiveness was EDTAFM greater than Zn-DTPA greater than Ca-DTPA greater than CaNa2-EDTA.