Novel choline transport characteristics in Caco-2 cells

Choline transport is characterized by sodium-dependent high-affinity, sodium-independent low-affinity, and sodium-independent blood-brain barrier transport mechanisms. Each defined mechanism has specific characteristics with regard to affinity for choline, transport capacity, and inhibition by hemicholinium. The purpose of this study is to determine the characteristics of choline transport across Caco-2 monolayers. Methods. Choline transport across Caco-2 cell monolayers was determined in both the apical to basal direction and the opposite direction. Further, the determination of calcium dependence and specific inhibitors was made. Determination of the apparent permeability of choline was calculated by established methods. Results. The apical to basal Caco-2 permeability coefficient is 11.11 ± 0.33 × 10^-6 cm/sec with 21.3% of the choline associating with the cells. Meanwhile the basal to apical value is approximately 50% less (5.55 ± 0.14 × 10^-6 cm/sec), suggesting an active apical to basal transport mechanism. Choline transport in this system was inhibited by nifedipine (82%), verapamil (80%), EGTA (36%), and cyclosporin (15%). Conclusions. Choline transport across Caco-2 cells is demonstrated to be active and both pH- and Ca²⁺-dependent. Furthermore, choline transport across Caco-2 monolayers has unique characteristics when compared to traditional choline transport models.     

Proton MR spectroscopy of childhood adrenoleukodystrophy

PURPOSE: To determine the potential of proton MR spectroscopy to monitor patients with childhood-onset cerebral adrenoleukodystrophy (COCALD). METHODS: Single-voxel MR spectroscopy was performed in 16 children with COCALD (24 examinations) who had had no treatment and in 7 children (13 examinations) who had had bone marrow transplantation. RESULTS: In the untreated children with clinically active COCALD, the metabolite ratios N-acetyl-aspartate (NAA)/creatine (Cr) and NAA/choline (Ch) were decreased while Ch/Cr was increased. This trend agrees well with those reported by other researchers, although different experimental sequences and parameters were used in our study. Comparison of these ratios with those from a control group yielded significant differences in the occipital region. In the children who were clinically stable after bone marrow transplantation, the mean levels of the three ratios were between those of the control subjects and the patients with untreated COCALD: the differences in these ratios approached significance. In patients who had been monitored periodically, MR spectroscopy metabolite ratios correlated well with the dementia rating score, reflecting clinical status. CONCLUSION: There is good correlation between MR spectroscopy metabolite ratios and a patient's clinical status. MR spectroscopy appears to be a useful, noninvasive tool to monitor patients with adrenoleukodystrophy, and it increases the overall sensitivity of MR techniques in clinical applications.     

Investigation of forming-gas annealed CeO<Subscript>2</Subscript> thin film on GaN

The effects of post-deposition annealing temperatures (400, 600, 800, and 1,000°C) in forming gas (95% N₂ + 5% H₂) ambient on metal–organic decomposed cerium oxide (CeO₂) thin films deposited on n-type GaN substrate had been investigated. The occurrence of CeO₂ phase transformation was reported and presence of CeO₂, α-Ce₂O₃, and β-Ga₂O₃ had been detected, depending on the annealing temperature. As the annealing temperature increased, grain size and microstrains of CeO₂ films were, respectively, increased and reduced. Metal–oxide–semiconductor characteristics of the annealed samples were systematically investigated. The highest dielectric breakdown field was perceived by sample annealed at 400°C due to the reduction of semiconductor–oxide interface trap density and effective oxide charge.     

生物医用植入体钛基合金及其表面生物活性氧化层的制备:机遇与挑战

钛及其合金因其优异的力学性能和良好的生物相容性,长期以来一直被用作植入材料.尽管如此,研究人员和行业仍在积极寻求更好的合金,因为仍有一些迫切的问题需要关注,包括:(1)由于种植体材料与人体骨组织的弹性模量不匹配而导致的应力屏蔽问题;(2)Ti合金长期使用后有害离子的释放问题;(3)钛合金表面生物活性低而导致愈合过程延长...     

Characteristics of APA members in the 1962 "National Scientific Register."

8650 (45%) of 19,370 National Register of Scientific and Technical Personnel questionnaires mailed to American Psychological Association members were returned within a month. Analysis of a 5% sample (432) provides the following information. New York, New Jersey, Pennsylvania, Illinois, Indiana, Michigan, Ohio, and Wisconsin produced, trained, and employed approximately ? of the 1962 sample. 69% had the doctorate, 28% masters, and 4% bachelor's degree. Age range of respondents was 23-90; median 38. Principal employers were colleges, 39%, and governmental organizations, 28%. Primary full time work activities were clinical and counseling practice 28%, teaching and research 21%, management and administrative tasks, 14%. Median income for full-time employed psychologists was nearly $11,000. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of applied voltage and fluoride ion content on the formation of zirconia nanotube arrays by anodic oxidation of zirconium

Anodised zirconium (Zr) foil at 20 V for 1 h in Na₂SO₄ with 0.5 wt.% NH₄F resulted in 6 μm thick anodic oxide film with nanotubular structure. At 50 V the anodic layer is consisted of an irregular inner layer with the nanotubular structure only at the top of the layer. Nonetheless, the anodic oxides formed are crystalline and photocatalytic ability of the anodic oxide was assessed by photodegradation of methyl orange.     

Rapid formation of transparent CuAlO2 thin film by thermal annealing of Cu on Al2O3

An 850-nm-thick CuAlO₂ film was formed by solid state reaction of evaporated thin film Cu on c-cut Al₂O₃ (sapphire) at 1200 °C for reaction times as short as 10 min. X-ray diffractogram confirms the formation of (0 0 l) CuAlO₂, indicating oriented growth of CuAlO₂ on c-cut Al₂O₃. Fourier transformation infra-red (FTIR) spectra showed peaks corresponding to Cu-O, Al-O and O-Cu-O bonds, confirming further the CuAlO₂ phase formation. UV-visible spectrum measurement showed high transparency of the film in the visible region with a direct band gap of 3.25 eV. The mechanism of the formation of the film is discussed.     

Fabrication of well-crystallized mesoporous ZrO2 thin films via Pluronic P123 templated sol–gel route

Mesoporous zirconia (ZrO₂) thin films were prepared by dip-coating via Pluronic P123 templated sol–gel route. ZrOCl₂·8 H₂O was used as zirconium (Zr) precursors. Annealing of as-coated ZrO₂ thin films is important in order to stiffen the respective films and to remove the Pluronic P123. The mesoporous structure and crystallite size of ZrO₂ were characterized systematically by field-emission scanning electron microscope (FESEM), both low- and wide-angle X-ray diffraction, thermal analysis technique and Brunauer–Emmett–Teller method. At annealing temperature of 400 °C, amorphous ZrO₂ was transformed into tetragonal phase of ZrO₂ (t-ZrO₂). At 450 °C, t-ZrO₂ and monoclinic phase of ZrO₂ (m-ZrO₂) were obtained. By altering heating rate during annealing, volume fraction of t-ZrO₂ and m-ZrO₂ was changed. FESEM images showed that disordered mesostructures of ZrO₂ were formed after annealing. The surface area of mesoporous ZrO₂ obtained ranges from 54.33 to 93.39 m²/g.     

Some relationships between the MMPI and a problem checklist.

Problem Checklist responses and MMPI T-scores were obtained for 335 male and 125 female student counselees. The most frequently checked problems dealt with educational and vocational difficulties, and males were nearly twice as variable as females in number of problems checked. "In general, there seems to be some logical correspondence between several of the Checklist problems and personality characteristics as assessed by the MMPI… [but]… Since the number of individuals in most of the high scale groups was so small… valid inference from the… results is impossible." (PsycINFO Database Record (c) 2010 APA, all rights reserved)