Bibliothek

Notizen: The property of extreme ultraviolet (EUV) generation from Xe clusters irradiated with intense lasers was studied. The Xe cluster jet was well characterized by the interferometric method. In order to obtain the adequate irradiation condition for strong EUV generation, EUV spectra were taken with various laser systems. Then, the wavelength, the pulse width, and the pump energy were widely varied. Through this survey, even with the comparatively low-density Xe jet of ≤5×1018 cm−3 average atomic density, the highest conversion efficiency of over 10% from laser energy to EUV (5–18 nm) was obtained with a subpicosecond KrF laser pulse, where a 4π source was assumed. This EUV source is considered to be attractive as an EUV lithography light source because of its low average atomic density and small Xe cluster. © 2001 American Institute of Physics.

Notizen: A niobium membrane was immersed in hydrogen plasma and could be electrically biased to vary the energy of bombarding ions in the range of 1–200 eV. The fluxes of plasma driven absorption and permeation were almost entirely governed by incident suprathermal neutrals (mostly, thermal atoms), whose energy does not depend on membrane bias, but the ions of controllable energy do affect the neutral-induced permeation through modifying the membrane surface. At the zero bias a high temperature-independent plasma driven permeation (superpermeation) was observed alongside of an enhanced absorption. Bombardment by ions of an energy higher than 50 eV resulted in a sharp decrease of the plasma driven permeation/retention and in an acceleration of boundary processes of absorption/reemission of thermal molecules. At ion energies below 50 eV, the effect of ion bombardment on the plasma driven permeation and the kinetic coefficients of boundary processes were nonmonotonic in ion energy, having a maximum at ∼10 eV. Both an in situ doping with O of the bulk of Nb and a membrane temperature increase reduced the effects of ion bombardment to their complete disappearance. Responsible for that was the replenishment by means of surface segregation of an oxygen monolayer sputtered by ion bombardment. © 2001 American Institute of Physics.

Notizen: We previously demonstrated that Helicobacter pylori colonization evokes gastric mucosal inflammation and an extensive increase in lipid peroxides and glutathione in Mongolian gerbils. Zinc and its derivative, polaprezinc, have been reported to be potent antioxidants in gastric mucosa.〈section xml:id="abs1-2"〉〈title type="main"〉Aim:To examine the effect of polaprezinc on gastric mucosal oxidative inflammation in H. pylori-colonized Mongolian gerbils.〈section xml:id="abs1-3"〉〈title type="main"〉Methods:Sixty-eight male Mongolian gerbils were orally inoculated with H. pylori (ATCC43504, 5 × 108 CFUs/gerbil; H. pylori group) and 35 gerbils were inoculated with the culture media (control group). Twenty-two gerbils in the H. pylori and 13 gerbils in the control group were fed with diets containing polaprezinc (0.06%, 100 mg/kg, 10 times the usual clinical dose) (H. pylori + polaprezinc group, polaprezinc group). The remaining gerbils were fed a standard laboratory chow diet. Neutrophil infiltration, assessed histologically and by the activity of myeloperoxidase, the contents of CXC-chemokine (GRO/CINC-1-like protein) and the contents of thiobarbituric acid-reactive substances, was evaluated in each group 12 weeks after the inoculation. Separately, gastric mucosal leucocyte activation and capillary perfusion were also assessed using intravital microscopy 2, 4, 8 and 12 weeks after the inoculation.〈section xml:id="abs1-4"〉〈title type="main"〉Results:In all H. pylori-inoculated animals, the bacterial infection persisted throughout the experimental period. Gastric mucosal lesion formation in the H. pylori group was significantly inhibited in the H. pylori + polaprezinc group. Elevated levels of myeloperoxidase activity, GRO/CINC-1 and thiobarbituric acid-reactive substances in the H. pylori group at 12 weeks were attenuated significantly by polaprezinc treatment. Enhanced levels of venular leucocyte activation observed in the H. pylori group were attenuated significantly in the H. pylori + polaprezinc group during both the early phase (2 weeks) and late phase (12 weeks).〈section xml:id="abs1-5"〉〈title type="main"〉Conclusion:Polaprezinc inhibited H. pylori-associated gastric mucosal oxidative inflammation, including initial micro-vascular leucocyte activation, in Mongolian gerbils.

Notizen: We present a case of prurigo pigmentosa associated with vesicles that we call ‘vesicular prurigo pigmentosa’. The subject was treated using minocycline with good results and no recurrence of the lesions over a 2-year period.

Notizen: We reported on a case of subcutaneous panniculitis-like T-cell lymphoma (SPTCL) with multiple erythematous nodular lesions on the extremities, trunk and face. Histological examination of an excised lesion revealed a dense infiltrate of markedly atypical T-lymphoid cells expressing the CD8+ phenotype located in the subcutaneous tissue with histiocyte-phagocytizing apoptotic cells. The ‘bean-bag’ histiocytic cells, the characteristic finding of SPTCL, are considered to be products of haemophagocytosis. In our case the ‘bean-bag’ cells were produced by phagocytosis of apoptotic bodies, as confirmed by electron microscopy. It is suspected that ‘bean-bag’ cells are related not to haemophagocytosis but to phagocytosis of apoptotic cells in the CD8+ T-cell type of SPTCL.

Notizen: Background Ultraviolet (UV) B-induced immunosuppression, implicated in the pathogenesis of skin cancers, is postulated to be mediated in part by cis-urocanic acid (cis-UCA) via tumour necrosis factor (TNF)-α. TNF-α produces morphological changes in Langerhans cells indistinguishable from those induced by UVB exposure and antibodies against TNF-α have been demonstrated to inhibit UVB-induced immunosuppression in vivo. Objectives To clarify further the role of TNF-α in UVB-induced immunosuppression and in cis-UCA immunosuppression. Methods We performed a contact hypersensitivity (CHS) assay on gene-targeted mutant mice (TNFR1R2–/–) lacking genes for both receptors (p55 and p75) for TNF-α. Mice were either irradiated with UVB or injected intradermally with cis-UCA, sensitized with 2,4-dinitrofluorobenzene, challenged on the ears and the response was measured. Results The TNFR1R2–/– mice showed hyporesponsiveness in the CHS response compared with wild-type (P 〈 0·001), confirming the proinflammatory role of TNF-α. However, significant suppression of CHS was seen after irradiation and after cis-UCA injection in both locally (sensitization on irradiated site; P 〈 0·05) and systemically (sensitization on non-irradiated site; P 〈 0·05) sensitized wild-type and gene-targeted mice. Conclusions These results demonstrate that TNF-α signalling is only partially involved in UVB-induced immunosuppression and does not play a major part in the cis-UCA immunosuppression mechanism.

Notizen: A new method of margin evaluation in breast conservation surgery using an adjustable mould during fixation Aims: We have developed a new method of breast resection margin assessment in quadrantectomy using an adjustable mould to prevent the three-dimensional specimen from distorting during fixation. Methods and results: The new method has been applied to 10 consecutive quadrantectomies (six invasive duct carcinomas, four duct carcinoma in situ with or without microinvasion). The precise configuration of the fixed specimen enabled pathologists to examine the side slices, the 5 mm thick slices cut parallel to the flat lateral margins of the specimen, permitting the separation of margin evaluation from tumour characterization. Eight cases with negative margins by our method would also be negative by assessment of inked margins since the margin widths were estimated to be from 5 to 30 mm (average 16.3 mm); two cases with positive margins would also be positive by inked margins. Conclusions: Our new method was as reliable as the inked margins employing sequential slicing of the entire tissue, although it reduced the number of blocks by more than half in invasive carcinomas. A further advantage of this method is that the accuracy in margin evaluation is not influenced by the extent of tumour sampling. In addition, our system can pinpoint the positive margins facilitating re-excision to obtain tumour-free margins.