Sapphire-based graphene saturable absorber for long-time working femtosecond lasers.

We report a long-time working femtosecond laser using metal-free sapphire-based graphene as a saturable absorber (SA). The sapphire-based graphene yielded excellent nonlinear saturable absorption properties and was demonstrated to be suitable as an SA for an ultrafast solid-state laser. Stable mode-locked pulses of 325 fs were obtained at a central wavelength of 1032 nm with a repetition rate of 66.3 MHz. At pump power of 8.23 W the average output power was 1.78 W and the highest pulse energy reached 26.8 nJ with a peak power of 72.6 kW. Our work opens up a facile route for making reliable graphene SA in the mode-locking technique and also displays an exciting prospect in making low-cost and ultrafast lasers.

The pathogenic detection for 126 children with diarrhea and drug sensitivity tests.

OBJECTIVE: To investigate the cause of infective diarrhea in children, special distribution of the infection and the drug sensitivity. PATIENTS AND METHODS: We carried out pathogenic detection and drug sensitivity tests for one hundred and twenty-six children with diarrhea, including 67 children in infant group (0-<1 year) and 59 children in child group (1-5 years). RESULTS: Fat particles and starch particles were seen in most stool samples under microscope; 42 kinds of pathogenic bacteria were obtained from 126 stool samples, including 10 Diarrheagenic E. coli (8 Enteropathogenic E. coli and Enteroinvasive E. coli); there were found 53 positive samples in the detection of anti-rotavirus antibody in 126 stool samples; in the drug sensitivity tests for major pathogenic bacteria, Staphylococcus aureus, Shigella, Salmonella and Diarrheagenic E. coli were highly sensitive. CONCLUSIONS: The abuse of antimicrobial agents may result in intestinal disorders, leading to aggravation in diarrhea and antimicrobial agents based on drug sensitivity tests may be served as fundamental treatment of diarrhea for children.

Two different histamine-sensitizing activities of pertussis vaccine observed in mice on the 4th and 12th days of sensitization.

The histamine-sensitizing (HS) activities of commercial precipitated diphtheria-tetanus-purified pertussis combined vaccines (DTP) submitted to the national quality control tests during the period from 1980 to 1991 were measured in mice on days 4 (EHS) and 12 (LHS) of sensitization. Annual averages of the EHS activity of the vaccines showed continuous decline during the period, while the LHS activity stayed unchanged except for 1990 and 1991. Correlation analysis between these two HS activities revealed that the vaccines could be differentiated into two groups, those showing a significant correlation and those lacking it, depending on their source manufacturers. When the vaccine was incubated at 37 C for four weeks, both the HS activities increased for the first couple of weeks at different rates, reaching their peaks after different periods; three weeks for the EHS activity and two weeks for the LHS activity. Treating the reference pertussis vaccine (for toxicity tests) with anti-pertussis toxin horse serum neutralized completely the EHS activity but the LHS activity resisted the serum. These findings suggest a possible difference between the two HS activities in their mode of action, therefore, in their roles in possible reactogenicity of the vaccine, and a necessity for separate controls of the two activities.