Enhanced efficiency of AlGaInP disk laser by in-well pumping.

The performance of a 665-nm GaInP disk laser operated continuous-wave at 15°C both in-well-pumped at 640 nm and barrier pumped at 532 nm is reported. The efficiency with respect to the absorbed power was enhanced by 3.5 times when using a 640-nm pump instead of a 532-nm pump. In-well pumping which is based on the absorption of the pump photons within the quantum-well heterostructures of the gain region instead of short-wavelength absorption in the barrier and spacer regions reduces the quantum defect between pump and laser photon and hence the heat generation. A slope efficiency of 60% with respect to the absorbed pump power was obtained by in-well pumping at 15°C. Continuous-wave laser operation was further demonstrated at heat sink temperatures of up to 55°C. Both the measurement of photoluminescence and COMSOL simulation show that the overall heat load in the in-well pumped laser is smaller than in the barrier-pumped laser. These results demonstrate the potential of optical in-well pumping for the operation of red AlGaInP disk lasers if combined with means for efficient pump-light absorption.

The 2018 hot drought pushed conifer wood formation to the limit of its plasticity: Consequences for woody biomass production and tree ring structure.

Hot droughts are expected to increase in Europe and disturb forest ecosystem functioning. Wood formation of trees has the potential to adapt to those events by compensatory mechanisms between the rates and durations of tracheid differentiation to form the typical pattern of vital wood anatomical structures. We monitored xylogenesis and measured wood anatomy of mature silver fir (Abies alba Mill.) and Scots pine (Pinus sylvestris L.) trees along an elevational gradient in the Black Forest during the hot drought year of 2018. We assessed the kinetics of tracheid differentiation and the final tracheid dimensions and quantified the relationship between rates and durations of cell differentiation over the growing season. Cell differentiation kinetics were decoupled, and temperature and water availability signals were imprinted in the tree ring structure. The sudden decline in woody biomass production provided evidence for a disruption in carbon sequestration processes due to heat and drought stress. Growth processes of Scots pine (pioneer species) were mainly affected by the spring drought, whereas silver fir (climax species) growth processes were more disturbed by the summer drought. Our study provides novel insights on the plasticity of wood formation and carbon allocation in temperate conifer tree species in response to extreme climatic events.

Studies on locus expansion, library representation, and chromosome walking using an efficient method to screen cosmid libraries.

We have developed an efficient screening method to search for clones in cosmid libraries prepared from human genomic DNA. Genomic, cDNA, and cosmid probes have been used to isolate homologous cosmids from human chromosomes 7, 10, 16, 17 and X as part of a search for polymorphic nucleotide sequences. This method has been successfully applied to chromosome walking experiments at the interstitial retinol-binding protein locus on chromosome 10, and may be a useful tool for investigating representation of cloned sequences in cosmid libraries. Our library was prepared in the vector c2RB (Bates and Swift, 1983), but the method is applicable to any cosmid cloning system in which the inserted DNA can be separated from the vector by restriction enzyme digestion. A cosmid library containing five human genome equivalents can be rapidly screened using three to four Southern hybridization filters. This results in substantial labor saving, particularly when screening genomes of high complexity with many different probes. Another advantage of the system is that it allows for the long-term storage of the cosmids so that they can be screened whenever necessary. As a consequence, cosmid screening can be made a routine laboratory procedure.

Degradation of household biowaste in reactors.

Household derived biowaste was degraded by biological methods. The system involves the combined method of low-solids (up to 10% w/v of total solids (TS)) anaerobic digestion and aerobic degradation for the recovery of energy (biogas) and the production of fine humus-like material which can be used as a soil amender or a substrate for further thermal treatment (pyrolysis, gasification). The performance of batch and continuous processes carried out in bioreactors (stirred tank reactor, air-lift) of working volume 6 and 18 dm(3), at different temperatures (25-42 degrees C) was monitored by reduction of TS, volatile solids, chemical oxygen demand, total organic carbon, C/N in time. The application of continuous process with recirculation (33%) caused that for residence time of 8-16 h the obtained degree of organic load reduction was similar to that obtained after 72-96 h of the batch process. The experimental data of batch aerobic degradation was also subjected to kinetic analysis. The sequence of the two processes: aerobic and anaerobic or anaerobic and aerobic showed that the degree of organic load reduction was similar in both cases, while the amount of produced biogas was four times higher when the first stage was anaerobic. The final product after dewatering was subjected to pyrolysis and gasification. The gases obtained were characterised by a high heat of combustion of about 11-15 MJ Nm(-3).

Flow cytometric determination of aminopeptidase activities in viable cells using fluorogenic rhodamine 110 substrates.

Aminopeptidases (AP) are ubiquitously occurring, nonspecific exopeptidases involved in protein degradation. They cleave the N-terminal amino acid of peptides and occur in practically all mammalian cells and tissues. Physiological and pathological processes such as metastasis of tumors and inflammation have been thought to involve changes in AP activities. Determination of AP (EC 3.4.11.X) activity in viable cells by flow cytometry was the subject of this study because of its general biological and clinical interest. Different bis-substituted rhodamine 110 (R110) peptide derivatives were synthesised and used as AP- and exopeptidase (EC 3.4.13.X-EC 3.4.14.X) substrates for flow cytometric measurements. Intracellular AP activities in viable lympho-, mono-, granulo-, and thrombocytes were detected by fluorescence increase from R110 following intracellular substrate cleavage. Eukaryotic-AP do not cleave D-amino acids and hence NH2(D-Leu)2R110 substrate served as negative control. Specific substrate cleavage by AP is shown by complete inhibition of flFLuorescence generation following preincubation of cells with leucine-chloromethylketone inhibitor. R110 AP- and exopeptidase substrates are suitable indicators for coupled endopeptidase reactions due to their rapid cleavage and largely pH independent generation of intracellular fluorescence.

New possibilities of cytostatic drug testing on patient tumor cells by flow cytometry.

A new assay for cytostatic drug testing is described which can be automated. Pleural effusions and ascites are cultured as such for one week. Cells of solid tumors are cultured in the patients own serum for the same time. The cells are then stained with the esterase and intracellular pH-indicator dye 1,4-diacetoxy-2,3-dicyano-benzene (ADB) to label vital cells. They are simultaneously stained with propidium iodide (PI) as an indicator for dead cells. Monosized fluorescent latex particles are added as concentration, volume and fluorescence standard. Inflammatory cells can be distinguished in the assay from tumor cells because of their small cell volume. The number of dead and surviving cells is counted by the flow cytometer and a therapeutic index is calculated as ratio between the surviving inflammatory to surviving tumor cells. An important feature of the assay is that the DNA-distribution of the dead cells (e.g. aneuploidy) as well as the functional state of the surviving tumor cells and inflammatory cells can be judged from intracellular esterase activity and intracellular pH.

Prognostic value of flow cytometrically determined DNA-ploidy, intracellular pH and esterase activity of non-small cell lung carcinomas.

30 surgical specimens of patients with non-small cell lung carcinomas (NSCLC) were investigated. Significant increases of intracellular pH values in epithelial and inflammatory cells, in the percentage of dead epithelial and inflammatory cells and in the cell volume of vital inflammatory cells in cancerous lung tissue were encountered. Furthermore, decreases of the esterase activity of vital epithelial cells and of the percentage of free cell nuclei were observed. The DNA aneuploidy in 36.6% of the tumours was frequently associated with non-squamous cell carcinomas and stage II, III, IV tumours. Patients with DNA aneuploid tumours had a significantly shorter survival rate than those with DNA euploid tumours. Within the different tumour stages a similar tendency was observed which was, however, only significant in stage III tumour patients. Stage III tumours constitute therefore a heterogeneous entity with a worse prognosis for DNA aneuploid tumour patients. The intracellular pH values and esterase activity as well as the cell volume, the percentage of free cell nuclei and dead inflammatory or epithelial cells contained no significant prognostic information.

Intracellular pH, esterase activity, and DNA measurements of human lung carcinomas by flow cytometry.

An important intention of flow cytometric investigations is to obtain biochemical and biophysical information about cells which is suitable for automated tumor diagnosis. In this study, the ploidy status, the intracellular pH value, the intracellular esterase activity, and the cell volume of vital cells and the DNA and cell volume of dead cells were measured in cancerous tissue and normal lung tissue of 30 patients by flow cytometry. The cell samples were simultaneously stained with the pH and esterase indicator dye 1.4-diacetoxy-2,3-dicyanobenzene (ADB) and propidium iodide (PI). The flow cytometric measurements were performed in three-parameter list mode. The data were evaluated on an AT-compatible personal computer with the DIAGNOS1 program system for automated diagnosis of flow cytometric list mode data. Significant differences were found between normal and malignant tissue in DNA ploidy, in the intracellular esterase activity, in the cell, volume and in the percentage of inflammatory cells and parameters of necrosis. DNA-aneuploidy was observed in 38% of the lung carcinomas. The simultaneous detection of DNA-aneuploidy and tumor-associated properties in a multifactorial analysis led to correct automatic tumor diagnosis in 85% of cases. DNA-aneuploidy was found at a significant higher frequency in advanced tumors. Adenocarcinomas displayed DNA-aneuploidy more often (80%) than squamous cell carcinomas (33%).

Identification and characterization of 23 RFLP loci by screening random cosmid genomic clones.

As part of our search for polymorphic DNA probes, we have screened cosmids from a human genomic DNA library for their ability to reveal RFLPs. A total of 101 randomly isolated cosmid clones were tested in Southern hybridizations for polymorphic band patterns. Fifty-four of these clones revealed RFLPs with one or more of nine restriction enzymes. Twenty-three of these clones have been further characterized and assigned to 10 different chromosomes by linkage analysis or by hybridization to panels of human-hamster hybrid cell lines. Fifteen of the probes have heterozygosities greater than or equal to .5. The relative efficiency of RsaI and PstI restriction enzymes in detecting polymorphism was different from results obtained with libraries constructed in bacteriophage vectors. Screening randomly selected cosmid probes is an efficient method for detecting RFLPs.

A genetic linkage map of 32 loci on human chromosome 10.

We have constructed a genetic linkage map of human chromosome 10 based on DNA probes that detect 47 restriction fragment length polymorphisms (RFLPs) at 32 different loci. Segregation data were collected on a set of multigenerational families provided by the Centre d'Etude du Polymorphisme Humain and maps were constructed using recently developed multipoint analysis techniques. The length of the sex-averaged map is 178 cM and the sex-specific map lengths are 131 cM in males and 255 cM in females. Recombination is significantly higher in female meioses. The mean distance between loci is 5.6 cM for the sex-averaged map. The genetic map spans the length of the chromosome as judged by physical localization of probes by in situ hybridization techniques and mapping of the probes on human-hamster hybrid cell lines containing all or part of chromosome 10. The informativeness of two loci near the locus responsible for multiple endocrine neoplasia type 2A (MEN-2A) has been increased by isolation of cosmids that reveal additional RFLPs at these loci.