Widely tunable multimode-interference based coupled cavity laser with integrated interferometer.

We present a simple to process tunable laser, fabricated in a low-cost generic fabrication process and based on two coupled Fabry-Perot cavities. The complex coupling coefficients of the coupling element are analytically derived from a 3×3 MMI using coupled mode theory and chosen to maximize the SMSR during lasing operation. Additionally, one of the cavities contains a reflective interferometer, which acts as coarse wavelength selector.

Low-loss passive waveguides in a generic InP foundry process via local diffusion of zinc.

Generic InP foundry processes allow monolithic integration of active and passive elements into a common p-n doped layerstack. The passive loss can be greatly reduced by restricting the p-dopant to active regions. We report on a localized Zn-diffusion process based on MOVPE, which allows to reduce waveguide loss from 2 dB/cm to below 0.

Coupled cavity laser based on anti-resonant imaging via multimode interference.

We report the experimental demonstration of two coupled laser cavities via self-imaging interference in a multimode waveguide. The coupling is optimized by considering images formed by two coherent phase-delayed signals at the input of a 3×3 splitter. As a result, the complex transfer coefficients of the coupling element can be chosen to increase the mode selectivity of the coupled system.

High-efficiency ultrasmall polarization converter in InP membrane.

An ultrasmall (<10  μm length) polarization converter in InP membrane is fabricated and characterized. The device relies on the beating between the two eigenmodes of chemically etched triangular waveguides. Measurements show a very high polarization conversion efficiency of >99% with insertion losses of <-1.

Directional control of optical power in integrated InP/InGaAsP extended cavity mode-locked ring lasers.

We report on a passively mode-locked InP/InGaAsP multiple quantum well semiconductor ring laser that operates at a 20 GHz repetition rate and around 1575 nm wavelength. The device has been realized using the active-passive integration technology in a standardized photonic integration platform. We demonstrate experimentally for the first time to our knowledge that the relative positioning of the amplifier and absorber in a monolithically integrated ring laser can be used to control the balance of power between counterpropagating fields in the mode-locked state.

Developmental Aspects of Immunoglobulins and Antibodies.

This short review discusses the evolution of the immunoglobulins and the development of the diversity of antibodies. Birds and mammals represent two lines of development having divided more than 300 million years ago. In the immunoglobulins and antibody-systems there are many similarities which, however, are based on analogies.

[Comparative studies of the detection of antibodies against BHV-5 using the enzyme-linked immunosorbent assay, serum neutralization test, cell assay and immunofluorescence test].

A comparison of the analyses of 490 serum samples from various flocks of sheep for the detection of BHV-5 antibodies using ELISA, serum neutralisation test, cell assay and immunofluorescence assay showed nearly identical results regarding the distinction between positive and negative serum samples. The percentage of serum samples with antibodies against BHV-5 antigen differed from test to test: ELISA 268 (54.7%), cell assay 323 (65.

[Development of an enzyme-linked immunosorbent assay for the detection of antibodies against bovine herpesvirus type 5 (BHV-5) in sheep sera].

The indirect enzyme-linked immunosorbent assay (ELISA) was first developed for the detection of antibodies against BHV-5 in sheep sera. Investigations of various antigen (Ag) preparations revealed that BHV material which had been purified across a sucrose gradient using sonification followed by ultracentrifugation gave satisfactory results during application in ELISA. Optimal coating of the solid phase was achieved with Ag adsorption at 4 degrees C overnight with 5 micrograms of virus material/ml in a carbonate-bicarbonate-buffer, pH 9.

[Quantitation of Acinetobacter calcoaceticus in mixed bacterial cultures by an enzyme immunoassay].

An enzyme-linked immunosorbent assay using polyclonal antibodies from rabbits has been developed for quantification of Acinetobacter calcoaceticus. Bacteria were added to the wells of a microtiter plate coated with anti-Acinetobacter immunoglobulin. For detecting bound cells the peroxidase-labelled immunoglobulin fraction was used.

The MTT-assay as a rapid test for cell proliferation and cell killing: application to human peripheral blood lymphocytes (PBL).

The possibility to use the colorimetric MTT assay for measuring proliferation and cell death of human peripheral blood lymphocytes (PBL) was studied. In a range from 100,000-800,000 cells/well a linear correlation between the optical signal (OD signal at 570 nm) and the cell number was found. It is necessary to incubate the cells with the MTT at least 2 hours.

[The importance of the endogenous agent and environmental factor thiocyanate for nonspecific and specific resistance from the hygienic viewpoint].

Thiocyanate (previous designation rhodanide, SCN-) is a physiological substance which is ubiquitously spread in the animate nature. As an essential constituent of cell it participates in important physiological resp. biochemical processes.

[Initial experiences in diagnosis of graft rejection following clinical heart transplantation. Detection of graft-directed activated T-cells].

The binding of antigen-loaded carrier to mononuclear cells of heart transplant recipients has been investigated by means of an antigen-specific rosette technique. The increase of rosette forming cells and the inhibition of this reaction with monoclonal antibodies against activated T-cells is a sign of a beginning rejection. 3-6 days later infiltrating immunological competent cells are seen in biopsy.

[Effect of Schistosoma mansoni infection on the immune reactions against heterologous antigens in mice].

Mice (BALB/c or ICR) were infected with Schistosoma mansoni cercariae. After different intervals (mostly eight weeks) the following antigens were injected: a) sheep erythrocytes--b) DNP-thyroglobulin. Afterwards the immune response against these antigens were checked by means of different methods (plaque assay, haemagglutination test, rosette technique).

[Immunoenzyme assay of parasite-specific IgG4 antibodies in schistosomiasis using the monoclonal antibody BL-IgG4/1].

Sera from 251 children living in endemic areas (Schistosoma mansoni or Schistosoma haematobium) and from 188 hospital outpatients in Ethiopia were evaluated for specific IgG4 antibodies reacting with Schistosoma mansoni adult worm antigen employing an enzyme-immunoassay. Patients with schistosomiasis (n = 140) possessed a significantly higher mean value of specific IgG4 antibodies than normal controls (n = 30) and individuals from different countries who had no schistosomiasis but are infected with other parasites (n = 114). Blood samples dried on filter paper were also acceptable in these test.

Culture and stimulation of human T- and B-lymphocytes.

The cultivation and stimulation of human peripheral blood cells by different mitogens were studied using a serum-free culture technique. It shows the possibility to culture human PBL in a commercially available serum-free medium over a period of at least 7 days. In a serum-free medium with high protein content the viability of the cells was higher than in one with low protein content or in a serum containing medium.

Surface immunoglobulin on lymphocytes of the tortoise Agrionemys horsfieldii.

Surface immunoglobulin bearing (sIg+) cells were identified in the tortoise Agrionemys horsfieldii by indirect immunofluorescence by using class-specific antisera to tortoise IgM and IgY produced in mice. With this technique 13-23% of blood lymphocytes were found to bear surface IgM and 5-8% IgY. Spleen lymphocytes show a higher percentage of sIg+ cells: 25-52% sIgM+ and 5-20% sIgY+ lymphocytes.

Immunohistochemical characterization of lymphocyte populations in carp (Cyprinus carpio L.).

Surface immunoglobulin-bearing cells from peripheral blood, thymus, head kidney, and spleen in carp (Cyprinus carpio L.) were studied by immunoperoxidase labelling using antisera against fragments of carp IgM. Different lymphoid cell populations could be determined.

Comparative studies on the structure of biliary immunoglobulins of some avian species. I. Physico-chemical properties of biliary immunoglobulins of chicken, turkey, duck and goose.

In pooled bile of chicken, turkey, duck and goose immunoglobulins (Igs)+ were found in relatively high amounts between 4.5 and 15.0 mg/ml (corresponding to 28 to 36% of the total protein contents).

Comparative studies on the structure of biliary immunoglobulins of some avian species. II. Antigenic properties of the biliary immunoglobulins of chicken, turkey, duck and goose.

Studies on the immunological cross-reactivity of the Igs+ from the bile of chicken and turkey (order Galliformes) as well as duck and goose (order Anseriformes) to Igs with antigenic known properties carried out by a series of RIA. Various class-specific anti-Ig sera produced in rabbits, guinea-pigs and mice were used. The following results were obtained: (1) A high extent of antigenic relationship between the chicken and turkey biliary Igs was demonstrated by a radiobinding system consisting of 125I-turkey biliary Ig and class-specific rabbit anti-turkey biliary Ig antibodies.

Anti-dextran antibodies of carp detected by the enzyme-linked immunosorbent assay (ELISA).

Carp produce anti-alpha (1-6) dextran antibodies after immunization with a vaccine of Leuconostoc mesenteroides B512. These antibodies can be determined by passive haemagglutination, quantitative precipitation or by ELISA. In our hands the ELISA has proved to be 100 times more sensitive than the passive haemagglutination test.

The immune response of carp against dextran. An analysis of the idiotype heterogeneity.

The expression of a "species-specific" idiotype with specificity for alpha(1-6) dextran in carp is described. All tested carp anti-dextran antisera react with a rabbit anti-Id (carp anti-dex) serum. The rabbit anti-Id serum can be partially inhibited by the specific ligand, dextran T70 or isomaltodecaose but not or only weak with other, unrelated carbohydrates.