Fabrication of oriented ZnO nanorod arrays and their optical performances

The well-aligned ZnO nanorod arrays were fabricated through a simple chemical process under low temperature. The nanorod arrays were characterized by XRD, SEM, TEM, HRTEM and SAED, and their optical performances were investigated with Raman and PL spectroscopy. The results show that the as-prepared ZnO nanorod arrays are dense, the individual ZnO nanorod is hexagonal shape and grows along c-axis perpendicular to the substrate surface with good single crystal in nature. The Raman property of nanorod arrays displays change with the altering the preparation conditions. Moreover, the PL performances of ZnO nanorod arrays exhibit tunable character with adjusting the synthesis conditions.

Intense beam production of highly charged heavy ions by the superconducting electron cyclotron resonance ion source SECRAL

There has been increasing demand to provide higher beam intensity and high enough beam energy for heavy ion accelerator and some other applications, which has driven electron cyclotron resonance (ECR) ion source to produce higher charge state ions with higher beam intensity. One of development trends for highly charged ECR ion source is to build new generation ECR sources by utilization of superconducting magnet technology. SECRAL (superconducting ECR ion source with advanced design in Lanzhou) was successfully built to produce intense beams of highly charged ion for Heavy Ion Research Facility in Lanzhou (HIRFL). The ion source has been optimized to be operated at 28 GHz for its maximum performance. The superconducting magnet confinement configuration of the ion source consists of three axial solenoid coils and six sextupole coils with a cold iron structure as field booster and clamping. An innovative design of SECRAL is that the three axial solenoid coils are located inside of the sextupole bore in order to reduce the interaction forces between the sextupole coils and the solenoid coils. For 28 GHz operation, the magnet assembly can produce peak mirror fields on axis of 3.6 T at injection, 2.2 T at extraction, and a radial sextupole field of 2.0 T at plasma chamber wall. During the commissioning phase at 18 GHz with a stainless steel chamber, tests with various gases and some metals have been conducted with microwave power less than 3.5 kW by two 18 GHz rf generators. It demonstrates the performance is very promising. Some record ion beam intensities have been produced, for instance, 810 e microA of O(7+), 505 e microA of Xe(20+), 306 e microA of Xe(27+), and so on. The effect of the magnetic field configuration on the ion source performance has been studied experimentally. SECRAL has been put into operation to provide highly charged ion beams for HIRFL facility since May 2007.

Extreme ultraviolet narrow band emission from electron cyclotron resonance plasmas

Extreme ultraviolet lithography (EUVL) is considered as the most promising solution at and below dynamic random access memory 32 nm half pitch among the next generation lithography, and EUV light sources with high output power and sufficient lifetime are crucial for the realization of EUVL. However, there is no EUV light source completely meeting the requirements for the commercial application in lithography yet. Therefore, ECR plasma is proposed as a novel concept EUV light source. In order to investigate the feasibility of ECR plasma as a EUV light source, the narrow band EUV power around 13.5 nm emitted by two highly charged ECR ion sources -- LECR2M and SECRAL -- was measured with a calibrated EUV power measurement tool. Since the emission lines around 13.5 nm can be attributed to the 4d-5p transitions of Xe XI or the 4d-4f unresolved transition array of Sn VIII-XIII, xenon plasma was investigated. The dependence of the EUV throughput and the corresponding conversion efficiency on the parameters of the ion source, such as the rf power and the magnetic confinement configurations, were preliminarily studied.

Experimental study of hot electrons in LECR2M plasma

In order to investigate the hot electron component in electron cyclotron resonance (ECR) plasmas, the volume bremsstrahlung spectra in the x-ray photon energy range were measured with a high-purity germanium detector on Lanzhou ECR Ion Source No. 2 Modified (LECR2M). A collimation system similar to Bernhardi's was used to focus at the central part of the plasma. The ion source was operated under various source conditions with argon; sometimes oxygen was added to enhance high charge state ion beam intensities. The spectral temperature of hot electrons T(spe) was derived from the measured bremsstrahlung spectra. The evolution of the deduced temperature of hot electrons T(spe) with the ion source parameters, such as the rf frequency, power, and the magnetic confinement configuration, was investigated.

An electron cyclotron resonance ion source based low energy ion beam platform

To satisfy the requirements of surface and atomic physics study in the field of low energy multiple charge state ion incident experiments, a low energy (10 eV/q-20 keV/q) ion beam platform is under design at IMP. A simple test bench has been set up to test the ion beam deceleration systems. Considering virtues such as structure simplicity, easy handling, compactness, cost saving, etc., an all-permanent magnet ECRIS LAPECR1 [Lanzhou all-permanent magnet electron cyclotron resonance (ECR) ion source No. 1] working at 14.5 GHz has been adopted to produce intense medium and low charge state ion beams. LAPECR1 source has already been ignited. Some intense low charge state ion beams have been produced on it, but the first test also reveals that many problems are existing on the ion beam transmission line. The ion beam transmission mismatches result in the depressed performance of LAPECR1, which will be discussed in this paper. To obtain ultralow energy ion beam, after being analyzed by a double-focusing analyzer magnet, the selected ion beam will be further decelerated by two afocal deceleration lens systems, which is still under design. This design has taken into consideration both ions slowing down and also ion beam focusing. In this paper, the conceptual design of deceleration system will be discussed.

Polarity determination for the CdxZn1-xS nanocombs by EELS

Comb-like Cd(x)Zn(1-x)S nanostructures have been synthesized by one-step metallo-organic chemical vapor deposition (MOCVD). The microstructure and composition were characterized by analytical transmission electron microscopy (TEM). The ribbon of the comb-like structure is along [2-1-10] (the a-axis), and the nanotips are along [0001] (the c-axis). The atomic location by channeling-enhanced microanalysis (ALCHEMI) technique was used to determine the polarity of the crystal via electron energy-loss spectroscopy (EELS). The thickness dependence, delocalization and beam convergent effect are discussed here. The investigations reveal that the growth mechanism is consistent with the asymmetric growth.

PMN degranulation in relation to CD63 expression and genetic polymorphisms in healthy individuals and COPD patients

Polymorphonuclear neutrophils (PMNs) play an important role in chronic obstructive pulmonary disease (COPD) pathogenesis. The tetraspanin CD63 is a membrane marker of azurophilic granules and is actively involved in the process of PMN endocytosis and azurophilic granule exocytosis. In this study, we investigated genetic polymorphisms of the CD63 gene, quantified CD63 expression and PMN myeloperoxidase (MPO) release in healthy individuals and COPD patients. We evaluated the potential correlations between genetic polymorphisms and gene expression and MPO release. COPD patients had significantly lower CD63 expression and released less MPO upon chemokine stimulation compared with the healthy individuals. Eleven putative polymorphisms in the CD63 gene were investigated but only three were polymorphic in our study subjects. None of the polymorphisms was associated with CD63 expression in either the healthy subjects or the COPD patients. However, the 8041C/G polymorphism, which is located 3' to the CD63 gene, was associated with MPO release in the healthy subjects. The CC genotype was associated with greater MPO release than the GG genotype (P=0.007). These results suggest that COPD patients have different patterns of CD63 expression and PMN mediator release than healthy individuals. It is likely that genetic variants have limited effect on CD63 expression and MPO release in the context of COPD but their role in other diseases has yet to be determined.

36-segmented high magnetic field hexapole magnets for electron cyclotron resonance ion source

Two high magnetic field hexapoles for electron cyclotron resonance ion source (ECRIS) have successfully fabricated to provide sufficient radial magnetic confinement to the ECR plasma. The highest magnetic field at the inner pole tip of one of the magnets exceeds 1.5 T, with the inner diameter (i.d.)=74 mm. The other hexapole magnet provides more than 1.35 T magnetic field at the inner pole tip, and the i.d. is 84 mm. In this article, we discuss the necessity to have a good radial magnetic field confinement and the importance of a Halbach hexapole to a high performance ECRIS. The way to design a high magnetic field Halbach structure hexapole and one possible solution to the self-demagnetization problem are both discussed. Based on the above discussions, two high magnetic field hexapoles have been fabricated to be utilized on two high performance ECRISs in Lanzhou. The preliminary results obtained from the two ECR ion sources are given.

Manipulation of dendritic cells for host defence against intracellular infections

Dendritic cells (DCs) are an important innate immune cell type which is the bridge between innate and adaptive immunity. Mounting experimental evidence suggests that manipulating DCs represents a powerful means to enhance host defence against intracellular infectious diseases. We have developed several strategies to manipulate DCs either in vivo or in vitro for the purpose of enhancing the effect of vaccination or immunotherapeutics. In vivo delivery of transgene encoding GM-CSF (granulocyte/macrophage colony-stimulating factor), a DC-activating cytokine, increases the number and activation status of DCs at various tissue sites and enhances antimicrobial immune responses in murine models. Co-expression or co-delivery of GM-CSF gene transfer vector with an antimicrobial vaccine enhances microbial antigen-specific T-cell responses and immune protection. Murine bone marrow-derived DCs are being manipulated in vitro and exploited as a vaccine delivery system. Transduction of DCs with a virus-vectored tuberculosis vaccine is a powerful way to activate T-cells in vivo. Such genetically modified DC vaccines can be administered either parenterally or mucosally via the respiratory tract.

Clinical research on monitoring CSFP through lumbar epidural pressure

OBJECTIVE

Explore the relationship between lumbar Epidural Pressure (LEDP) and CSFP through clinical studies and to determine whether LEDP can represent CSFP.

METHODS

We selected 150 cases of cerebral diseases at random for this study. A special mini transducer was implanted into the lumbar epidural space between the third and the 4th lumbar vertebra by means of a No. 18 Touhy needle for monitoring of LEDP. In the meantime, a traditional lumbar puncture was made between the 4th and the 5th lumbar vertebrae and CSFP, which was taken as the standard value, was measured using an ordinary catheter. The transducer was adjusted until the LEDP was equal to CSFP and was designated LEDP0. The LEDP0 was monitored continuously and was translated into a continuous curve. In each and every case, a lumbar puncture was repeated at 24, 48, 72 and 96 hours to obtain CSFP for comparison and to explore the relationship between LEDP0 and CSFP. While monitoring LEDP0, we observed the variation in pressure when the patient breathed, coughed, changed posture, and also if the clinical symptoms changed with intracranial hypertension.

RESULT

The values of the intracranial pressure measured by these two methods were identical.

CONCLUSION

LEDP responded to the changes of CSFP.

Determination of Salbutamol in Human Plasma and Urine by High-Performance Liquid Chromatography with a Coulometric Electrode Array System

A method is developed to determine salbutamol in human plasma and urine using high-performance liquid chromatography (HPLC) with a coulometric electrode array system, based on the electrochemical behavior of salbutamol at graphite electrode. The mobile phase component A is 30 mM sodium dihydroxy phosphate-30 mM triethylamine and is adjusted to pH 6.0 with 20% phosphate acid. The mobile phase component B is methanol. The optimized mobile phase composition was A and B in the proportion of 90:10 (v/v). Paracetamol is selected as the external standard. The human plasma and urine samples are pretreated using solid-phase extraction cartridges (Sep-Pak Silica), and the eluting solution is monitored by the coulometric electrode array system. The electrode potentials are set at 300, 400, 550, and 650 mV, respectively. Calibration curves show good linearity, and the recovery of salbutamol proves to be constant and unaffected by the concentration of the drug. This method, developed using HPLC-electrochemical detection, is reproducible and sensitive enough for the determination of salbutamol in human plasma and urine.

[Effects of Rholida on the free radical metabolism and serum creatine kinase after exercise at plateau]

Objective. To study the effect of Rholida on free radical metabolism and serum creatine kinase CK) after exercise at plateau. Method. After staying at high altitude (4100 m) for 20 d, 40 healthy young men were divided into 4 groups randomly (Rholida, Acetazolamide, Xi' s capsule and control, 10 men each group). And their SOD, MDA, GSH-Px CK, and CK-MB were determined respectively. Before, after taking drugs and after finishing the 5 min-stair-exercise. Result. Before taking drugs and after exercise, MAD GSH-Px, CK, CK-MB, increased as compared with quiet state (P<0.05, P<0.01), but SOD showed no significant chang (P>0.05). After taking drugs for 6 d, those who took Rholida, Acetazolamide and Xi's capsule, their MAD, GSH-Px CK, CK-MB increased after exercise as compared with quiet state (P<0.05). In Rholida group SOD increased and had significant change (P<0.05); but there was no significant change in Acetazolamide, Xi' s capsule group, SOD increased, MDA decreased (P<0.05), CK, CK-MB had no significant change (P>0.05), GSH-Px increased in Xi's group (P<0.05), but not in Acetazolamide group (P>0.05). SOD, GSH-Px increased, MDA, CK-MB decreased in Rholida group after taking drugs and the changes were significant (P<0.01). In Acetazolamide and Xi's capsule group, GSH-Px increased significantly, MDA, CK, CK-MB decreased significantly (P<0.05), but SOD didn't (P>0.05). Conclusion. Rholida, Acetazolamide, Xi's capsule could regulate the disorder of free radical metabolism at plateau and Rholida had advantage over the others.

[The changes of coagulation and fibrinolysis function on hypoxia adaptation mechanism]

AIM AND METHODS

To determine their Antithrombin-III (AT-III), Plasminogen (PLG), D-Dimer (DD), tissue-Plasminogen Activator (t-PA), Plasminogen Activator Inhibitor (PAI), Fibrinogen (Fg) and alpha2-Plasmin, inhibitor (alpha2-PI), when 40 subjects entered to high altitude, and compared with healthy flatlander.

RESULTS

At high altitude (3 700 m, 5 380 m) the AT-III abd t-PA were lower significantly than that of the flatlander (1 400m) (P < 0.05 or P < 0.01). The higher altitude subjects enter, the lower count will take (P < 0.01), and with the longer stay time, there was a higher count (P < 0.05 or P < 0.01). The 7th day at high altitude, PLG. DD. PAI. alpha2-PI and Fg were much higher than the flatlander's (P < 0.05 or P < 0.01), and with the higher elevation, there were higher datas, and with the longer stay time, there were lower datas (P < 0.05 or P < 0.01). Compare the a half of year at 3 700m with the flatlands, the results isn't discrepant (P > 0.05).

CONCLUSION

There is a coagulation-function disorder at high altitude, the results shows that coagulation and fibrinolysis are activated and fibrinolysis is inhibited yet, so the coagulation-fibrinolysis balance is destroyed. This effects lead to a hypercoagulation and hypo fibrinolysis state.

L-arginine supplementation in young renal allograft recipients with chronic transplant dysfunction

AIMS

L-arginine (LA), the precursor of nitric oxide (NO), was suggested to be beneficial in many forms of renal disease: hypertension, ureteral obstructive nephropathy and cyclosporin A (CsA) nephrotoxicity.

METHODS

Thus, we investigated the effects of LA supplementation on renal function, proteinuria and blood pressure (BP) in young renal allograft recipients with chronic renal transplant dysfunction treated with CsA. Eleven CsA-treated renal allograft recipients with chronic transplant dysfunction, aged 11-22 years, were randomly assigned to a 6-week treatment period with placebo (P), followed by 2 subsequent 6-week periods with LA supplementation (0.1 g/kg body weight/day) or a 6-week treatment period with LA, followed by 2 subsequent 6-week periods with P. At the end of each treatment period 24-hour BP recordings were made, and GFR (Inutest), RPF (PAH clearance) and the urinary excretion of protein, albumin, nitrate, cGMP and urea were evaluated.

RESULTS

In comparison to placebo, LA treatment did not significantly change GFR, RPF, proteinuria and albuminuria, mean systolic or diastolic BP. The urinary excretion of urea and NO3 increased after LA supplementation (uUrea: LA 26.3 +/- 4.6 compared to P 23.5 +/- 4.7 g/day/1.73 m3, p < 0.05, uNO3: LA 514 +/- 152 compared to P 95 +/- 41 mM/day/1.73 m3, p < 0.05), whereas urinary excretion of cGMP remained unchanged.

CONCLUSION

LA supplementation did not improve renal function and did not decrease proteinuria in CsA-treated renal allograft recipients with chronic transplant dysfunction possibly because of inhibition of NO-cGMP forming mechanism.

Effects of Tween-80 on the biodistribution of several lipophilic technetium-99m complexes

The effects of Tween-80 on the biodistributions in mice of (99m)Tc-TBI, (99m)Tc-MIBI, (99m)TcN-TBI and (99m)TcN-MIBI were reported. The studies resulted that liver and blood uptakes of Tween-80 added (TA) complexes significantly lower than that of corresponding non-Tween-80 added (NTA) complexes. And the clearance rate from blood of TA complexes faster than that of NTA complexes. The optimal concentration of Tween-80 was about 1%. It can decrease the lipophilicity of (99m)Tc-complexes and improve the biological properties of the lipophilic (99m)Tc-complexes for myocardial imaging. It's worthy for further studies.

[Determination of O6-methylguanine by high performance capillary zone electrophoresis]

In this paper, a method to determine O6-methylguanine in urine by high performance capillary zone electrophoresis has been established. O6-methylguanine was directly introduced into the capillary employing sodium borate at pH 9.0 as buffer. The capillary used was 75 microns i.d. x 57 cm. The calibration curve showed good linearity, r = 0.9987, CVs were 1.51% for intra-day and 1.93% for inter-day. The average recovery was 98.2%. In conclusion, this method is a simple, rapid, precise and reliable technique for O6-methylguanine measurement in urine.

[Determination of rufloxacin in human plasma by high performance liquid chromatography]

A high performance liquid chromatographic method has been developed for the determination of rufloxacin in human plasma. Rufloxacin was extracted from plasma with dichloromethane for three times. It was chromatographed on an Ultrasphere ODS column with Pefloxacin as internal standard with a mobile phase consisting of methanol-tetrabutylammonium bromide-triethanolamine (32:68:0.5, V/V) adjusted to pH 2.8 with orthophosphoric acid. The flow rate was 1.2 mL/min and the monitoring wavelength was 295 nm. The calibration curve was linear from 0.1 to 10 mg/L of plasma. The detection limit of rufloxacin was 0.05 mg/L for plasma and the recovery was (97.7 +/- 2.1)%. The intra-day RSD and inter-day RSD were 2.33% and 3.38% respectively. The method is simple, rapid, accurate and can be used to determine the rufloxacin concentration in plasma and for pharmacokinetic study.

Optical profilometric study of changes in surface roughness of enamel during in vitro demineralization

The application of non-contact optical profilometry for non-destructive study of changes in the surface roughness of natural enamel surfaces during in vitro demineralization was investigated. Repeated measurement of profiles of the same enamel surfaces after successive demineralization episodes was achieved by a kinematic specimen mount that could be removed, then accurately repositioned. Surface roughness parameters and reflectivity of natural enamel surfaces exposed to either a demineralizing solution (test) or deionized water (control) for up to 6 days were measured at 6- to 24-hour intervals. The results prior to demineralization showed that surface roughness varies with position on the enamel surface. During demineralization there was an approximately linear increase in surface roughness for the first 70 h followed by somewhat erratic behaviour, and a saturating exponential with time increase in reflectivity for the first 70 h which subsequently remained constant. Changes in enamel surface during in vitro demineralization were also observed using scanning electron microscopy.

Renal and metabolic effects of L-arginine infusion in kidney transplant recipients

AIM AND METHODS

In order to investigate the role of kidney damage on renal response to L-arginine (L-Arg) infusion in transplant patients receiving cyclosporine A (CsA) treatment, we assessed systemic and glomerular hemodynamic variables, the fraction excretion of urinary sodium, albumin, cyclic GMP (as an index of nitric oxide (NO) production from L-Arg) and urea excretion (as an index of ureagenesis), and glucoregulatory hormone levels in five normal volunteers and 21 renal allograft recipients (aged 10-20 years) treated with CsA, 10 with normal renal function and 11 with chronic renal insufficiency.

RESULTS

In the normal subjects, L-Arg infusion (290 mg/min/1.73 m2 for 1 h) significantly reduced mean arterial pressure (MAP) (76+/-7 to 70+/-5 mmHg) and renal vascular resistance (RVR), and increased GFR (103+/-9 to 122+/-7 min/1.73 m2), RPF, urinary cyclic GMP excretion (0.40+/-0.1 to 0.60+/-0.1 nmol/100 ml glomerular filtrate (GF)), and sodium and albumin excretion. Neither the patients with chronic graft dysfunction nor those with a normal graft responded to L-Arg infusion: RVR remained high, and MAP, GFR, RPF, fractional excretion of sodium and urinary excretion of albumin and cyclic GMP were unchanged in both groups of patients. Glucagon, insulin and urinary urea excretion rose significantly in controls and both patient groups.

CONCLUSION

The hemodynamic effects of L-Arg infusion were inhibited in the patients, regardless of their degree of renal function, possibly because L-Arg-NO production was blunted.

The effects of gonadectomy on bone size, mass, and volumetric density in growing rats are gender-, site-, and growth hormone-specific

Peak volumetric bone mineral density (BMD) is determined by the growth in bone size relative to the mineral accrued within its periosteal envelope. Thus, reduced peak volumetric BMD may be the result of reduced mineral accrual relative to growth in bone size. Because sex steroids and growth hormone (GH) influence bone size and mass we asked: What are the effects of gonadectomy (Gx) on bone size, bone mineral content (BMC), areal and volumetric BMD in growing male and female rats? Does GH deficiency (GH-) reduce the amount of bone in the (smaller) bone, i.e., reduce volumetric BMD? Does GH- alter the effect of Gx on bone size and mineral accrual? Gx or sham surgery was performed at 6 weeks in GH- and GH replete (GH+) Fisher 344 male and female rats. Changes in bone size, volume, BMC, areal and volumetric BMD, measured using dual X-ray absorptiometry (DPX-L), were expressed as percentage of controls at 8 months (mean +/- SEM). All results shown were significant (p < 0.05 level) unless otherwise stated. In GH+ and GH- males, respectively, Gx was associated with: lower femur volume (24%, 25%), BMC (43%, 45%), areal BMD (21%, 14%), and volumetric BMD (30%, 28%); lower spine (L1-L3) volume (26%, 28%), BMC (26%, 30%), and areal BMD (28%, 12%), but not volumetric BMD. Following Gx, GH+ females had increased femur volume (11%), no effect on BMC, decreased areal BMD (6%) and decreased volumetric BMD (17%); GH- females had no change in femur volume, but decreased femur BMC (24%), areal BMD (10%), and volumetric BMD (25%). In GH+ and GH- females, respectively, Gx was associated with a decrease in spine (L1-L3) BMC (12%, 15%), areal BMD (16%, 15%), and volumetric BMD (10%, 16%) with no change in volume. Deficits in non-Gx GH- relative to non-Gx GH+ (males, females, respectively) were: femur BMC (49%, 37%), areal BMD (23%, 8%), volume (19%, 19%) and volumetric BMD (37%, 22%); spine (L1-L3) BMC (46%, 42%), areal BMD (37%, 43%), volume (10%, 15%), and volumetric BMD (40%, 33%). Testosterone and GH are growth promoting in growing male rats, producing independent effects on bone size and mass; deficiency produced smaller appendicular bones with reduced volumetric BMD because deficits in mass were greater than deficits in size. At the spine, the reduction in size and accrual were proportional, resulting in a smaller bone with normal volumetric BMD. In growing female rats, estrogen was growth limiting at appendicular sites; deficiency resulted in a GH-dependent increase in appendicular size, relatively reduced accrual, and so, reduced volumetric BMD in a bigger bone. At the spine, accrual was reduced while growth in size was normal, thus volumetric BMD was reduced in the normal sized bone. Understanding the pathogenesis of low volumetric BMD requires the study of the differing relative growth in size and mass of the axial and appendicular skeleton in the male and female and the regulators of the growth of these traits.

Endothelin mediates renal vascular memory of a transient rise in perfusion pressure due to NOS inhibition

We investigated the renal responses to NO synthase (NOS) inhibition with N-monomethyl-L-arginine (L-NMA; 30 mg/kg) in anesthetized rats in which renal perfusion pressure (RPP) to the left kidney was mechanically adjusted. Acute L-NMA increased blood pressure (BP, approximately 20%) and renal vascular resistance (RVR) rose ( approximately 50%) in the right kidneys that were always exposed to high RPP. In group 1, the left kidney was exposed to a transient increase (5 min) in RPP which was then normalized, and the rise in RVR was similar to the right kidney. In group 2 the left kidney was never exposed to high RPP, and the rise in RVR was attenuated relative to the right kidney. In group 3, rats were pretreated with the endothelin (ET) receptor antagonist Bosentan, immediately before exposure of the left kidney to a transient increase in RPP, and the rise in RVR was also attenuated relative to the right kidney. NOS inhibition resulted in a natriuresis and diuresis in the right kidneys, and approximately 50% of the natriuresis persisted in the left kidney of group 2, in the absence of any rise in RPP. ET antagonism completely prevented the natriuresis and diuresis in response to acute L-NMA in both left and right kidneys. These data suggest that transient exposure to high RPP by NOS inhibition prevents an appropriate vasodilatory response when RPP is lowered, due to the intrarenal action of ET.

Surface modification of A12O3 bioceramic by NH2+ ion implantation

Ion implantation technique was applied to graft the -NH2 amidogen radicals onto the surface of Al2O3 bioceramic. Fourier transform infrared spectroscopy (FTIR) was used to confirm the presence of the implanted radicals on the Al2O3 ceramic surface. It was found that the amount of grafted amidogen radicals was proportional to the dosage of NH2+ ions used during the ion implantation. Furthermore, when implantation energy of 100 keV was used, maximum amount of -NH2 radicals would be grafted on the Al2O3 ceramic surface. The biocompatibility of the implanted Al2O3 ceramic was also investigated, and the results indicate that the implanted surface has better biocompatibility with animal bone tissue than the plain ceramic surface.