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Notes: Carbon nitride films were synthesized on Si(100) substrate using relatively high-pressure radio-frequency magnetron sputtering of a graphite target in a nitrogen ambient. The influences of the substrate temperature and pressure on deposition rate and the film composition ratio N/C and C–N bonding were investigated using x-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR). The deposition rate had a maximum in the investigated pressure region and reduced as the substrate temperature increased. XPS spectra showed that the deposited films were very large N/C value up to 1.20, and unchanged after thermal treatment up to about 900 K, the latter confirmed by FTIR. © 1995 American Institute of Physics.

Notes: Depth profiles and annealing behaviors of hydrogen implanted into titanium samples at an energy of 10 keV per nucleon were measured in the implantation temperature and fluence ranges of 77–400 K and of 6.3×1016–3.3×1018 H/cm2, respectively. Trapping enthalpies are deduced from the annealing curves. It was found that the trapping mechanism of hydrogen implanted into Ti depends on both the temperature and the fluence at the implantation. When implanted at a temperature sufficiently higher than 273 K, hydrogen moves from the surface layer to an underlying bulk and precipitates as hydride irrespective of fluence. On the other hand, at a temperature around or below 273 K, the implanted hydrogen atoms are trapped by the vacancies at a low concentration of hydrogen. However, hydride formation is realized where the local atomic ratio of H/Ti becomes close to the stoichiometric value of TiH2.

Notes: Leaf photosynthesis (Ps), nitrogen (N) and light environment were measured on Populus tremuloides trees in a developing canopy under free-air CO2 enrichment in Wisconsin, USA. After 2 years of growth, the trees averaged 1·5 and 1·6 m tall under ambient and elevated CO2, respectively, at the beginning of the study period in 1999. They grew to 2·6 and 2·9 m, respectively, by the end of the 1999 growing season. Daily integrated photon flux from cloud-free days (PPFDday,sat) around the lowermost branches was 16·8 ± 0·8 and 8·7 ± 0·2% of values at the top for the ambient and elevated CO2 canopies, respectively. Elevated CO2 significantly decreased leaf N on a mass, but not on an area, basis. N per unit leaf area was related linearly to PPFDday,sat throughout the canopies, and elevated CO2 did not affect that relationship. Leaf Ps light-response curves responded differently to elevated CO2, depending upon canopy position. Elevated CO2 increased Pssat only in the upper (unshaded) canopy, whereas characteristics that would favour photosynthesis in shade were unaffected by elevated CO2. Consequently, estimated daily integrated Ps on cloud-free days (Psday,sat) was stimulated by elevated CO2 only in the upper canopy. Psday,sat of the lowermost branches was actually lower with elevated CO2 because of the darker light environment. The lack of CO2 stimulation at the mid- and lower canopy was probably related to significant down-regulation of photosynthetic capacity; there was no down-regulation of Ps in the upper canopy. The relationship between Psday,sat and leaf N indicated that N was not optimally allocated within the canopy in a manner that would maximize whole-canopy Ps or photosynthetic N use efficiency. Elevated CO2 had no effect on the optimization of canopy N allocation.

Notes: Broomrapes (Orobanche spp.) are parasitic weeds that cause significant losses of crop yield. Experiments were conducted to investigate the seed response to the artificial germination stimulant GR24 in three species of Orobanche subjected to preconditioning under various temperatures, water potentials and with plant growth regulators. The highest germination percentages were observed in Orobanche ramosa, Orobanche aegyptiaca and Orobanche minor seeds conditioned at 18°C for 7 days followed by germination stimulation at 18°C. With the increase of the conditioning period (7, 14, 21 and 28 days), the germination percentage of O. ramosa and O. aegyptiaca progressively decreased. When conditioned at −2 MPa, the germination percentage was lower than at 0 and −1 MPa, especially at 13 and 28°C. Orobanche minor seeds could retain relatively high germination if conditioned at 18, 23 or 28°C, even after significantly extended conditioning periods (up to 84 days). GA3 (30–100 mg L−1), norflurazon and fluridone (10–100 mg L−1), and brassinolide (0.5–1.0 mg L−1) increased seed germination, while 0.01 mg L−1 uniconazole significantly reduced germination rates of all three Orobanche spp. The promotional effects of GA3 and norflurazon and the inhibitory effect of uniconazole were evident, even when they were treated for 3 days. Germination of Orobanche seeds was much lower when the unconditioned seeds were directly exposed to GR24 at 10−6 m. This early GR24-induced inhibition was however alleviated or even eliminated by the inclusion of GA3 or norflurazon (10–50 mg L−1) in the conditioning medium. On the contrary, the inclusion of uniconazole increased the inhibitory effect of GR24, particularly in the case of O. ramosa.

Notes: Hexamethylenetetramine is an odourless powder and slowly liberates formaldehyde in an acid medium or when heated, It is usually used in the manufacture of formaldehyde resins, rubber and the explosive. cyclonite. It is also used as a hardener in core molding processes. It was reported us one of the formaldehyde releasers and is a cause of formaldehyde contact dermatitis. We report art allergic contact dermatitis due ID hexamethylenetetramine. With a positive patch test reaction to hexamethy-lenetetramine (1% pet.) but not to formaldehyde (2% aq.). We concluded that this case was an allergic contact dermatitis from hexamethylenetetramine itself.

Notes: Activated T lymphocytes constitute a major component of inflammatory cells in the early periodontal lesion, and also appear in the gingival crevicular fluid. In an attempt to clarify the relationship between the ICAM-1 (CD54) expression of pocket epithelium in gingiva and the infiltrating lymphocyte population, we carried out an analysis of CD11a+ (LFA-lα), CD25+ (IL-2Rα) and CD4+ (Th) cells subjacent to ICAM-1-expressing pocket epithelia and CD11a+ CD25+CD4+ cells in gingival crevicular fluid (GCF). GCF was collected by crevicular washing from 16 patients with periodontitis (P group) and 3 subjects with healthy gingiva (H group). Peripheral blood (PB) was collected at the same time. Mononuclear cells were isolated by Ficoll-paque gradient centrifugation from GCF and PB. Monoclonal antibodies (mAb) to CD11a, CD25, and CD4 were used for three-color flow cytometry. Gingival biopsies were obtained from 7 patients in P group and 3 subjects in H group. Serial cryostat sections (6 μm in thickness) were prepared from each biopsy, on which a double staining was performed. The number of CD11a+ CD25+ CD4+ cells and the fluorescence intensity of FITC conjugated anti-CD 11a were significantly higher in GCF than in PB (p≤0.001 to p≤0.01). CD11a+ CD25+CD4+ cells were not detected in GCF in H group. The pocket epithelia expressed CD54 in P group, but not in H group. The number of CD11a+, CD25+ and CD4+cells infiltrating the connective tissue subjacent to the upper, middle and lower parts of the CD54 positive pocket epithelium (n=16) was 141±26, 38±13, 144±29 (cells/0.04 mm2), respectively, whereas in the CD54 negative pocket epithelium, it was (n=5) 9±2, 3±1, 8±3. In P group, the CD11a+CD25+CD4+cell number in GCF correlated with CD25+, CD11a+cells in the connective tissue subjacent to the CD54+pocket epithelium. These results indicate that expression of ICAM-1 in pocket epithelium is relevant to the migration of CD11a, CD25, CD4 positive cells in connective tissue subjacent to the pocket epithelium into the periodontal pocket. Assessing the relationship of our findings and other adhesion molecules would offer important clues to the understanding of T cell migration in affected gingiva.