Low-noise intelligent cladding-pumped L-band EDFA

We present results on a low-cost cladding-pumped L-band amplifier based on side pumping (GTWave) fiber technology and pumped by a single 980-nm multimode diode. We show that simultaneous noise reduction and transient suppression can be achieved by using gain clamping by a seed signal (/spl lambda/=1564 nm). In the gain-clamping regime, the amplifier exhibits 30-dB gain over 1570-1605-nm spectral band with noise figure below 7 dB. The noise figure can be further reduced to below 5 dB by utilizing a low power single-mode pump at 980 nm. The erbium-doped fiber amplifier is relatively insensitive to input signal variations with power excursions below 0.15 dB for a 10-dB channel add-drop.     

Inflammatory malignant fibrous histiocytoma: distinction from Hodgkin''s disease and non-Hodgkin''s lymphoma by a panel of leukocyte markers

The invariant chain (CD74) is preferentially localized in the cytoplasm and regulates the loading of exogenous derived peptides into HLA class II heterodimers. In addition, a small proportion of CD74:class II complexes is also expressed on the cell surface. We identified and quantified soluble CD74 (sCD74) molecules in the plasma and sCD74:sHLA-DR complexes by ELISA. EDTA plasma samples from 86 healthy probands were analyzed. sCD74 could be detected in all samples with a mean concentration of 1.14 relative units +/- 1.04 SD (range 0.17-4.31). Approximately 10% of the samples had increased amounts of sCD74 (>3.0 relative units). Complexes of sCD74 and sHLA-DR were detected in all samples and their quantities were positively correlated (r=0.83, p<0.001) with the sCD74 concentrations. SDS-PAGE analysis of plasma samples with high sCD74 concentrations (>3.0 relative units) revealed four isoforms of sCD74 with molecular weights of 45, 43, 35, 31 kDa corresponding to known sizes of intracellular CD74. However, only molecular weights of the 45 and 43 kDa isoforms of sCD74 are found complexed with sHLA-DR. Our data demonstrate, that CD74 molecules are present in their soluble form in the plasma of healthy probands and form complexes with soluble HLA-DR molecules.     

Evaluation of CD23 expression in paraffin-embedded gastric lymphomas of mucosa-associated lymphoid tissue

The CD23 antigen is expressed in a normal subset of B lymphocytes and in some non-Hodgkin's lymphomas. Reactivity for anti-CD23 (BU38) is present in paraffin-embedded tissue in the large majority of nodal small lymphocytic lymphomas, as well as in follicular center cell lymphomas. Most studies of gastric lymphomas of mucosa-associated lymphoid tissue (MALT) reported a lack of CD23, but these studies were performed on frozen tissue. We evaluated CD23 staining in paraffin-embedded tissue in a large series of gastric MALT lymphomas, as well as in cases of chronic gastritis. We assayed 49 well-characterized gastric lymphomas (9 high-grade non-MALT and 40 MALT [20 low grade, 13 mixed low and high grade, and 7 high grade]). High-grade MALT lymphomas without a low-grade component were distinguished from high-grade non-MALT lymphomas by the presence of lymphoepithelial lesions composed of large cells. In addition, we studies nine cases of chronic gastritis containing B-cell aggregates. We used anti-CD23 (BU38) in formalin-fixed, paraffin-embedded tissue. All of our low-grade gastric MALT lymphomas lacked CD23 immunoreactivity. One of the 13 mixed low-grade and high-grade lesions showed CD23 expression in the high-grade component. All of the high-grade MALT and high-grade non-MALT lesions lacked CD23. All of the nine cases of chronic gastritis lacked CD23. CD23 highlighted residual follicular dendritic cells and gastric epithelium. We concluded that gastric MALT lymphomas lacked CD23 (BU38) in paraffin-embedded tissue, with rare exceptions. This lack of CD23 expression might represent a useful feature in small or partially crushed biopsy specimens, particularly in the differential diagnosis with follicular small cleaved cell lymphoma presenting in the gastrointestinal tract.     

Lymphopain, a cytotoxic T and natural killer cell-associated cysteine proteinase

Through differential screening of established human leukaemia cell lines, we have identified and molecularly cloned lymphopain, a novel cysteine proteinase of the papain family. Lymphopain exhibits a remarkably restricted cellular pattern of expression, being predominantly expressed in cytotoxic T-lymphocytes and natural killer cells. The human lymphopain locus maps to chromosome 11q13, encodes a polypeptide of 376 amino acids and is conserved in the mouse. Both human and murine forms appear more closely related to protozoan papain-like enzymes than to other mammalian members of the papain family. The cellular distribution of lymphopain expression, together with the functional demonstration of lymphopain-associated proteinase activity in vitro, is suggestive of a role for lymphopain in immune cell-mediated, cell killing.     

Effects of ozone exposure on the xerophilic fungus, Eurotium amstelodami IS-SAB-01, isolated from naan bread

Xerophilic moulds cause contamination and spoilage of low moisture foods. This study examined the effect of ozone fumigation on growth of a Eurotium species isolated from naan bread. Two ozone treatments were used — a low-level long-term exposure (0.4 μmol/mol for 21 days) and high-level short-term exposure (300 μmol/mol for 5 to 120 min). For the low level exposure the combination of different media sucrose concentrations (0, 5, 10 and 20% w/v) with ozone treatment was also assessed. The growth of the isolate was found to be sensitive to low-level ozone fumigation depending on the media sucrose concentration and duration of the exposure. Low-level ozone exposure significantly (p < 0.05) reduced the number of asexual spores formed in media with no added sucrose, an effect not observed in media with higher sucrose levels. Electron microscope observations of colonies indicated that ozone exposed cultures produced lower numbers of cleistothecia. High-level ozone exposure for short durations reduced spore viability although 100% reduction in viability was achieved only after 120 min exposure. This work demonstrates that ozone may be used to reduce spore production in Eurotium but that the ozone effect can be mediated by sucrose levels in the growth medium.     

Pulsed laser deposition of indium tin oxide films on flexible polyethylene naphthalate display substrates at room temperature

Pulsed laser deposition was used to deposit high-quality indium tin oxide (ITO) thin solid films on polyethylene napthalate (PEN) flexible display substrates. The electrical, optical, microstructural, mechanical and adhesive properties of the functional thin layer were investigated as a function of a narrow range of background oxygen gas pressure at room temperature, which is the most desirable thermal condition for growing transparent conducting oxides on flexible display polymer substrates. ITO films (240 ± 35 nm thick) deposited on PEN at room temperature in the range of 0.33 to 2.66 Pa background oxygen pressure are observed to exhibit low electrical resistivity (~ 10^− 4 Ω cm) and high optical transmission (~ 90%). Electromechanical uniaxial tensile testing, of the hybrid thin structures, results in crack onset nominal strains of around 2%. The ITO surface adhesion reaches a maximum at 1.33 Pa deposition pressure.     

Crystal Structure and Antiferromagnetic Ordering of Quasi-2D [Cu(HF2)(pyz)2]TaF6 (pyz=pyrazine)

The crystal structure of the title compound was determined by X-ray diffraction at 90 and 295 K. Copper(II) ions are coordinated to four bridging pyz ligands to form square layers in the ab-plane. Bridging $\mathrm{HF}_{2}^{-}$ ligands join the layers together along the c-axis to afford a tetragonal, three-dimensional (3D) framework that contains $\mathrm{TaF}_{6}^{-}$ anions in every cavity. At 295 K, the pyz rings lie exactly perpendicular to the layers and cooling to 90 K induces a canting of those rings. Magnetically, the compound exhibits 2D antiferromagnetic correlations within the 2D layers with an exchange interaction of ?13.1(1) K. Weak interlayer interactions, as mediated by Cu-F-H-F-Cu, leads to long-range magnetic order below 4.2 K. Pulsed-field magnetization data at 0.5 K show a concave curvature with increasing B and reveal a saturation magnetization at 35.4 T.     

Hybrid antibody mediated veto of cytotoxic T lymphocyte responses

Strategies are being sought that allow the induction of specific tolerance to allogeneic transplants without affecting other immune functions. The so-called veto effect has been described as one such technology where CD8+ cells suppress responses of class I MHC-restricted T-lymphocyte precursors to antigens expressed by those CD8+ veto cells. Yet, veto inhibition will not be able to provide complete tolerance to allogeneic grafts since it only operates on cell populations that express CD8. Other types of cells prevalent in most organs express different tissue-specific antigens that are recognized by alloreactive T-cells. Therefore, complete tolerance to an allogeneic transplant can only be achieved if all cellular components within the graft acquire the immune-inhibitory function. Here, we studied whether the veto effect could be exploited for this purpose nevertheless. We produced a hybrid antibody (HAb) combining a mAb specific for a class I MHC molecule with a soluble CD8 molecule. We found that this HAb specifically and effectively transferred veto inhibition to different stimulator cell populations. Thus, we have developed a strategy that promises to selectively and completely tolerize graft-specific CTLs without affecting normal immune responses.     

Continuing medical education in mental illness: a paradox for general practitioners

BACKGROUND: In 1992, the Royal College of General Practitioners instituted its fellowship in mental health education, which aimed to provide general practitioner tutors with the skills they need to help general practitioners manage mental illness in general practice. However, the emphasis of the fellowship on pedagogic education may discourage educators wishing to introduce andragogic teaching, a paradox which general practitioners must resolve if the aims are to be realized. AIM: This study set out to follow the difficulties encountered by the regional fellows in managing the fellowship and to understand how the scheme has evolved. METHOD: Data collected for interim evaluation of the fellowship was studied and interviews undertaken with the senior fellow and the regional fellows participating in the scheme. RESULTS: From its beginnings, the project encountered difficulties involving acceptance among general practitioner tutors. In response to the objections raised, the project metamorphosed through three stages, from a (perceived) pedagogic approach to a much more overtly learner-centered one. CONCLUSION: Learner-centred education requires trust and belief in the ability of general practitioners to teach general practitioners; over-protection of the audience from 'non-expert' educators merely perpetuates the status quo. If education in mental health care is to become truly learner-centred, general practitioners must address this paradox.