The electrochemical oxide growth behaviour on titanium in acid and alkaline electrolytes

Titanium implants have a thin oxide surface layer. The properties of this oxide layer may explain the good biocompatibility of titanium implants. Anodic oxidation results in a thickening of the oxide film, with possible improved biocompatability of anodized implants. The aim of the present study was twofold: (1) firstly, to characterize the growth behaviour of galvanostatically prepared anodic oxide films on commercially pure (c.p.) titanium and (2) secondly, to establish a better understanding of the electroche0mical growth behaviour of anodic oxide on commercially pure titanium (ASTM grade 1) after changes of the electrochemical parameters in acetic acid, phosphoric acid, calcium hydroxide, and sodium hydroxide under galvanostatic anodizing mode. The oxide thickness was measured by Ar sputter etching in Auger Electron spectroscopy (AES) and the colours were estimated by an L*a*b* system (lightness, hue and saturation) using a spectrophotometer. In the first part of our study, it was demonstrated that the interference colours were useful to identify the thickness of titanium oxide. It was also found that the anodic forming voltages with slope (dV/dt) in acid electrolytes were higher than in alkaline electrolytes. Each of the used electrolytes demonstrates an intrinsically specific growth constant (nm/V) in the range of 1.4--2.78 nm/V. In the second part of our study we found, as a general trend, that an increase of electrolyte concentration and electrolyte temperature respectively decreases the anodic forming voltage, the anodic forming rate (nm/s) and the current efficiency (nm.cm(2)/C), while an increase of the current density and the surface area ratio of the anode to cathode increase the anodic forming voltage, the anodic forming rate and the current efficiency. The effects of electrolyte concentration, electrolyte temperature, and agitation speed were explained on the basis of the model of the electrical double layer.

Glucose metabolism in early onset versus late onset Alzheimer's disease: an SPM analysis of 120 patients

The aims of this cross-sectional study were (i) to compare the overall glucose metabolism between early onset and late onset Alzheimer's disease in a large sample of patients; and (ii) to investigate the pattern of glucose metabolism as a function of dementia severity in early onset versus late onset Alzheimer's disease, using a statistical parametric mapping (SPM) analysis. Subjects consisted of four groups: 74 patients with early onset Alzheimer's disease, 46 patients with late onset of the disease, and two control groups age matched to each patient group. All the subjects underwent 2-[(18)F]fluoro-2-deoxy-d-glucose (FDG)-PET under the same scanning conditions. Severity of dementia was rated with the Clincial Dementia Rating (CDR). Voxel-based SPM99 was used for statistical analyses. Overall glucose hypometabolism of early onset Alzheimer's disease patients was much greater in magnitude and extent than that of late onset patients, though both groups were similar in dementia severity: the early onset group showed more severe hypometabolism in parietal, frontal and subcortical (basal ganglia and thalamus) areas. When the decline of glucose metabolism was compared as a function of CDR stage, the slope was steeper in early onset than in late onset Alzheimer's disease. The rapid decline occurred at CDR 0.5-1 in the early onset group, whereas similar changes occurred at CDR 2-3 in the late onset group. The greater hypometabolism in early onset than in late onset patients is required to reach the same severity of dementia, probably reflecting greater functional reserve in younger than in older subjects. Alternatively, the metabolic decline curve suggests that the early onset patients may take a more rapid course in the reduction of glucose metabolism than the late onset patients.

Coherent manipulation of electronic States in a double quantum dot

We investigate coherent time evolution of charge states (pseudospin qubit) in a semiconductor double quantum dot. This fully tunable qubit is manipulated with a high-speed voltage pulse that controls the energy and decoherence of the system. Coherent oscillations of the qubit are observed for several combinations of many-body ground and excited states of the quantum dots. Possible decoherence mechanisms in the present device are also discussed.

Anodic oxide films containing Ca and P of titanium biomaterial

Anodic oxidation and oxide films of titanium in the new electrolyte of calcium glycerophosphate (Ca-GP) and calcium acetate (CA) were investigated by galvanostatic mode, SEM, XRD and EPMA. The anodic oxide film displayed porosity, intermediate roughness, and high crystallinity. Also, the oxide film is enriched with Ca and P and high in thickness without microcracks. According to the surface properties of the oxide film, the optimum condition was that the concentration of the electrolyte was 0.02 M Ca-GP and 0.15 M CA, and current density and final voltage were 70 A/m2 and ca. 350 V. The oxide film formed in the condition is 0.98 microm (Ra) rough, 5-7 microm thick, adhesive to the underlying substrate, and near 1.67 Ca/P ratio in the oxide film.

Effects of disease duration on the clinical features and brain glucose metabolism in patients with mixed type multiple system atrophy

To study the effect of disease duration on the clinical, neuropsychological and [(18)F]-deoxyglucose (FDG) PET findings in patients with mixed type multiple system atrophy (MSA), this study included 16 controls and 37 mixed-type MSA patients with a shorter than a 3-year history of cerebellar or parkinsonian symptoms. We classified the patients into three groups according to the duration of parkinsonian or cerebellar symptoms (Group I = <or=1 year; II = 13-24 months; III = 25-36 months). We performed UPDRS, international cooperative ataxia rating scale (ICARS), and a neuropsychological test battery. We compared the FDG PET findings of each group of patients with controls. Group I patients frequently had memory and frontal executive dysfunction. They showed hypometabolism in the frontal cortex, anterior cerebellar hemisphere and vermis. They had parkinsonian motor deficits, but no basal ganglia hypometabolism. Group II and III patients frequently had multiple domain cognitive impairments, and showed hypometabolism in the frontal and parieto-temporal cortices. Hypometabolism of the bilateral caudate and the left posterolateral putamen was observed in Group II, and whole striatum in Group III. In summary, the cortical hypometabolism begins in the frontal cortex and spreads to the parieto-temporal cortex in MSA. This spreading pattern coincides with the progressive cognitive decline. Early caudate hypometabolism may also contribute to the cognitive impairment. Parkinsonian motor deficits precede putaminal hypometabolism that begins in its posterolateral part. Cerebellar hypometabolism occurs early in the clinical courses and seems to be a relevant metabolic descriptor of cerebellar deficits.

Oxidized implants and their influence on the bone response

Surface oxide properties are regarded to be of great importance in establishing successful osseointegration of titanium implants. Despite a large number of theoretical questions on the precise role of oxide properties of titanium implants, current knowledge obtained from in vivo studies is lacking. The present study is designed to address two aspects. The first is to verify whether oxide properties of titanium implants indeed influence the in vivo bone tissue responses. The second, is to investigate what oxide properties underline such bone tissue responses. For these purposes, screw-shaped/turned implants have been prepared by electrochemical oxidation methods, resulting in a wide range of oxide properties in terms of: (i) oxide thickness ranging from 200 to 1000 nm, (ii) the surface morphology of barrier and porous oxide film structures, (iii) micro pore configuration - pore sizes<8 microm by length, about 1.27 microm2 to 2.1 microm2 by area and porosity of about 12.7-24.4%, (iv) the crystal structures of amorphous, anatase and mixtures of anatase and rutile type, (v) the chemical compositions of TiO2 and finally, (vi) surface roughness of 0.96-1.03 microm (Sa). These implant oxide properties were divided into test implant samples of Group II, III, IV and V. Control samples (Group I) were turned commercially pure titanium implants. Quantitative bone tissue responses were evaluated biomechanically by resonance frequency analysis (RFA) and removal torque (RT) test. Quantitative histomorphometric analyses and qualitative enzyme histochemical detection of alkaline (ALP) and acidic phosphatase (ACP) activities were investigated on cut and ground sections after six weeks of implant insertion in rabbit tibia. In essence, from the biomechanical and quantitative histomorphometric measurements we concluded that oxide properties of titanium implants, i.e. the oxide thickness, the microporous structure, and the crystallinity significantly influence the bone tissue response. At this stage, however, it is not clear whether oxide properties influence the bone tissue response separately or synergistically.

Suppressed pi(0) production at large transverse momentum in central Au+Au collisions at sqrt[s(NN)]=200 GeV

Transverse momentum spectra of neutral pions in the range 1<p(T)<10 GeV/c have been measured at midrapidity by the PHENIX experiment at BNL RHIC in Au+Au collisions at sqrt[s(NN)]=200 GeV. The pi(0) multiplicity in central reactions is significantly below the yields measured at the same sqrt[s(NN)] in peripheral Au+Au and p+p reactions scaled by the number of nucleon-nucleon collisions. For the most central bin, the suppression factor is approximately 2.5 at p(T)=2 GeV/c and increases to approximately 4-5 at p(T) approximately 4 GeV/c. At larger p(T), the suppression remains constant within errors. The deficit is already apparent in semiperipheral reactions and increases smoothly with centrality.

The brain lesion responsible for parkinsonism after carbon monoxide poisoning

BACKGROUND

Parkinsonism is a common neurological sequela of carbon monoxide (CO) poisoning, but its pathophysiological mechanism has yet to be clarified.

OBJECTIVES

To describe a married couple who were both affected by CO poisoning, but only 1 of whom developed CO-induced parkinsonism, and to discuss the possible underlying pathophysiological mechanism of CO-induced parkinsonism by comparing the neuroimaging findings of these patients.

DESIGN AND SETTING

Case report from a clinical neurology department.

PATIENTS

A married couple experienced CO poisoning simultaneously. One month later, only the husband gradually developed delayed sequelae, including parkinsonism and intellectual impairment. On detailed neurological examination, the husband showed mild but definite rigidity and bradykinesia, while no parkinsonian signs were observed in the wife. Neuropsychological examination revealed impaired memory and attention in both patients, but they were more severe in the husband than in the wife. Magnetic resonance imaging scans of the patients' brains disclosed diffuse high-intensity white matter signals in both patients and bilateral pallidal necrosis in the wife. Dopamine transporter imaging showed that the degree of dopamine neuronal loss was comparable between these patients. Magnetic resonance spectroscopy revealed more severe white matter damage in the husband than in the wife. Thirteen months later, neurological and neuropsychological examinations showed complete recovery from parkinsonism as well as intellectual impairment. Follow-up magnetic resonance spectroscopy also suggested remarkable improvements in white matter damage.

CONCLUSION

These results support the role of white matter damage in producing parkinsonism after CO poisoning and highlight the possible usefulness of magnetic resonance spectroscopy in predicting delayed sequelae in patients after CO poisoning. Arch Neurol. 2000;57:1214-1218

Stimulation of the lateral hypothalamus produces antinociception mediated by 5-HT1A, 5-HT1B and 5-HT3 receptors in the rat spinal cord dorsal horn

The lateral hypothalamus is part of an efferent system that modifies pain at the spinal cord dorsal horn, but the mechanisms by which lateral hypothalamus-induced antinociception occur are not fully understood. Previous work has shown that antinociception produced from electrical stimulation of the lateral hypothalamus is mediated in part by spinally projecting 5-hydroxytryptamine (5-HT) neurons in the ventromedial medulla. To further examine the role of the lateral hypothalamus in antinociception, the cholinergic agonist carbamylcholine chloride (125 nmol) was microinjected into the lateral hypothalamus of female Sprague-Dawley rats and nociceptive responses measured on the tail-flick and foot-withdrawal tests. Intrathecal injections of the selective 5-HT1A, 5-HT1B, 5-HT3 receptor antagonists, WAY 100135, SB-224289, and tropisetron, respectively, and the non-specific antagonist methysergide, were given. Lateral hypothalamus stimulation with carbamylcholine chloride produced significant antinociception that was blocked by WAY 100135, tropisetron, and SB-224289 on both the tail-flick and foot-withdrawal tests. Methysergide was not different from controls on the tail flick test, but increased foot-withdrawal latencies compared with controls. These results suggest that the lateral hypothalamus modifies nociception in part by activating spinally projecting serotonin neurons that act at 5-HT1A, 5-HT1B, and 5-HT3 receptors in the dorsal horn.

Pattern of glucose hypometabolism in frontotemporal dementia with motor neuron disease

Frontotemporal dementia (FTD) often coexists with motor neuron disease (MND). To characterize glucose hypometabolism in patients with FTD with MND (FTD/MND), the authors compared the glucose metabolism of 8 patients with FTD/MND with that of 29 patients with FTD. All of the patients with FTD/MND showed glucose hypometabolism only in the frontal area, whereas most patients with FTD had hypometabolism in the frontal and temporal areas. FTD/MND also showed a more symmetric pattern of glucose hypometabolism than FTD.

Glucose metabolism in sporadic Creutzfeldt-Jakob disease: a statistical parametric mapping analysis of (18) F-FDG PET

BACKGROUND AND PURPOSE

Reports describing functional neuroimaging techniques, such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT), in sporadic Creutzfeldt-Jakob disease (sCJD) have consistently suggested that these tools are sensitive for the identification of areas of hypoperfusion or hypometabolism, even in the early stages of sCJD. However, there are few reports on the use of [18F]fluoro-2-deoxy-D-glucose (FDG) PET in sCJD, and most of them are single case reports. Only two small cohort studies based on visual inspection or a region of interest method have been published to date. Using a statistical parametric mapping (SPM) analysis of (18) F-FDG PET, we investigated whether there are brain regions preferentially affected in sCJD.

METHODS

After controlling for age and gender, using SPM 2, we compared the glucose metabolism between (i) 11 patients with sCJD and 35 controls and (ii) the subset of five patients with the Heidenhain variant of sCJD and 35 controls.

RESULTS

The patients with sCJD showed decreased glucose metabolism in bilateral parietal, frontal and occipital cortices. The Heidenhain variant of sCJD showed glucose hypometabolism mainly in bilateral occipital areas.

CONCLUSIONS

Glucose hypometabolism in sCJD was detected in extensive cortical regions; however, it was not found in the basal ganglia or thalamus, which are frequently reported to be affected on diffusion-weighted images. The medial temporal area, which is possibly resistant to the prion deposits, was also less involved in sCJD.

Ytterbium-doped large-core fiber laser with 1.36 kW continuous-wave output power

We have demonstrated a highly-efficient cladding-pumped ytterbium-doped fiber laser generating 1.36 kW of continuous-wave output power at 1.1 mum with 83% slope efficiency and near diffraction-limited beam quality. The laser was end-pumped through both fiber ends and showed no evidence of roll-over even at the highest output power, which was limited only by available pump power.

Elliptic flow of identified hadrons in Au+Au collisions at sqrt sNN =200 GeV

The anisotropy parameter (v(2)), the second harmonic of the azimuthal particle distribution, has been measured with the PHENIX detector in Au+Au collisions at sqrt[s(NN)]=200 GeV for identified and inclusive charged particle production at central rapidities (|eta|<0.35) with respect to the reaction plane defined at high rapidities (|eta|=3-4 ). We observe that the v(2) of mesons falls below that of (anti)baryons for p(T)>2 GeV/c, in marked contrast to the predictions of a hydrodynamical model. A quark-coalescence model is also investigated.

Synthetic lethal screening reveals FGFR as one of the combinatorial targets to overcome resistance to Met-targeted therapy

Met is a receptor tyrosine kinase that promotes cancer progression. In addition, Met has been implicated in resistance of tumors to various targeted therapies such as epidermal growth factor receptor inhibitors in lung cancers, and has been prioritized as a key molecular target for cancer therapy. However, the underlying mechanism of resistance to Met-targeting drugs is poorly understood. Here, we describe screening of 1310 genes to search for key regulators related to drug resistance to an anti-Met therapeutic antibody (SAIT301) by using a small interfering RNA-based synthetic lethal screening method. We found that knockdown of 69 genes in Met-amplified MKN45 cells sensitized the antitumor activity of SAIT301. Pathway analysis of these 69 genes implicated fibroblast growth factor receptor (FGFR) as a key regulator for antiproliferative effects of Met-targeting drugs. Inhibition of FGFR3 increased target cell apoptosis through the suppression of Bcl-xL expression, followed by reduced cancer cell growth in the presence of Met-targeting drugs. Treatment of cells with the FGFR inhibitors substantially restored the efficacy of SAIT301 in SAIT301-resistant cells and enhanced the efficacy in SAIT301-sensitive cells. In addition to FGFR3, integrin β3 is another potential target for combination treatment with SAIT301. Suppression of integrin β3 decreased AKT phosphorylation in SAIT301-resistant cells and restored SAIT301 responsiveness in HCC1954 cells, which are resistant to SAIT301. Gene expression analysis using CCLE database shows that cancer cells with high levels of FGFR and integrin β3 are resistant to crizotinib treatment, suggesting that FGFR and integrin β3 could be used as predictive markers for Met-targeted therapy and provide a potential therapeutic option to overcome acquired and innate resistance for the Met-targeting drugs.

The highest prognostic impact of LDH among International Prognostic Indices (IPIs): an explorative study of five IPI factors among patients with DLBCL in the era of rituximab

Although the International Prognostic Index (IPI) is considered as the current standard prognostication system for diffuse large B-cell lymphoma (DLBCL), prognostic heterogeneity is suggested to exist among the patients within the same IPI risk group. Hence, we investigated the pattern of distribution and prognostic impact of five IPI factors within the same IPI score. We retrospectively reviewed the medical records of 387 patients newly diagnosed as pathologically proven DLBCL between February 2002 and February 2010. We classified patients to IPI risk scores and categorized them according to the combinations of IPI. Then, we explored the frequency of five IPI factors and analyzed the correlation between these subgroups and efficacy outcomes: complete response (CR), event-free survival (EFS), and overall survival (OS). Survival estimates by IPI score in this cohort corresponded to the classic IPI. Elevated serum level of lactate dehydrogenase (LDH) was the most prevalently distributed factor throughout the scores, and patients with elevated serum level of LDH tended to have lower CR, inferior EFS, and/or OS irrespective of IPI scores. Particularly, among the subgroups of IPI score of 2, elevated serum level of LDH was significantly associated with inferior CR (73.1 vs 95.2 %), 3-year EFS (57 vs 87 %), and 3-year OS (58 vs 82 %). In addition, the higher serum level of LDH, particularly above 2,000 IU/L, was significantly correlated with the inferior survival outcomes (3-year EFS 78.0 vs 58.5 vs 45.5 vs 20.0 %, 3-year OS 86.0 vs 66.2 vs 58.2 vs 40.0 %). In conclusion, among five factors of IPI, elevated serum level of LDH seems to be the most frequently distributed and, more importantly, the most relevant IPI factor with the highest prognostic impact. These findings still warrant further validation in larger cohorts.

Measurement of transverse single-spin asymmetries for midrapidity production of neutral pions and charged hadrons in polarized p + p collisions at square root(s) = 200 GeV

Transverse single-spin asymmetries to probe the transverse-spin structure of the proton have been measured for neutral pions and nonidentified charged hadrons from polarized proton-proton collisions at midrapidity and square root(s) = 200 GeV. The data cover a transverse momentum (pT) range 1.0-5.0 GeV/c for neutral pions and 0.5-5.0 GeV/c for charged hadrons, at a Feynman-x value of approximately zero. The asymmetries seen in this previously unexplored kinematic region are consistent with zero within errors of a few percent. In addition, the inclusive charged hadron cross section at midrapidity from 0.5 < pT < 7.0 GeV/c is presented and compared to next-to-leading order perturbative QCD (pQCD) calculations. Successful description of the unpolarized cross section above approximately 2 GeV/c suggests that pQCD is applicable in the interpretation of the asymmetry results in the relevant kinematic range.

Screening of hexavalent chromium biosorbent for marine algae

A high-chromate-selective biosorbent with high adsorption capacity was sought by examining the chromate adsorption capacities of 48 species of red, brown, or green marine algae sampled from the east coast of Korea. Screening showed a red marine alga to have the most excellent adsorption characteristics among them, and it was identified as Pachymeniopsis sp. The period at which Pachymeniopsis sp. was sampled did not affect the adsorption capacity of the alga, but the optimum period for mass collection was April to May. The alga also showed high selectivity for chromate since its adsorption capacity for other heavy metal ions such as cadmium and manganese ions was relatively low. An investigation of the adsorption isotherm of dried powder of Pachymeniopsis sp. for chromate adsorption at 25 degrees C showed a Langmuir-type dependence. The maximum chromate adsorption capacity of the selected alga was about 225 mg/g. Desorption of the adsorbed chromate from Pachymeniopsis sp. was done by treating the sample with 1 N NaOH. It was confirmed that ion exchange type adsorption was observed with an anion exchanger but not with a cation exchanger. It is therefore believed that the chromate adsorption is based on anionic exchange of Pachymeniopsis sp.

Midrapidity neutral-pion production in proton-proton collisions at square root s = 200 GeV

The invariant differential cross section for inclusive neutral-pion production in p+p collisions at sqrt[s]=200 GeV has been measured at midrapidity (|eta|<0.35) over the range 1<p(T) less, similar 14 GeV/c by the PHENIX experiment at the Relativistic Heavy Ion Collider. Predictions of next-to-leading order perturbative QCD calculations are consistent with these measurements. The precision of our result is sufficient to differentiate between prevailing gluon-to-pion fragmentation functions.