Ion-Doped Photonic Crystal Fiber Lasers.

Compared with conventional solid-state lasers, fiber lasers have the advantages of small size, simple cooling system, and good output beam quality, enabling them an extended service lifetime in industrialized environments. Periodically arranged photonic crystals have been the most important gain medium for high-power laser applications, which overcame the problems in fiber lasers such as small mode field, low degree of nonlinearity, and non-adjustable dispersion. In this mini-review, we summarize the recent advances of typical ion-doped photonic crystal fiber lasers doped, discuss the challenges, and provide an outlook on the future developments in ion-doped photonic crystal fiber lasers.

[Distribution Characteristics and Source Analysis of Polycyclic Aromatic Hydrocarbons in Salinized Farmland Soil from the Oil Mining Area of the Yellow River Delta].

Eighty-nine soil samples were collected from the Binzhou oil mining area of the Yellow River Delta (including 83 farmland soil samples and 6 soil samples from an oil extraction area). A total of 16 US-EPA priority polycyclic aromatic hydrocarbons (PAHs) were measured by gas chromatography-mass spectrometry (GC-MS). Principal component analysis (PCA) and positive matrix factorization (PMF) were employed to investigate potential source apportionment of PAHs in the farmland soil. The total PAH concentrations ranged from 31.5 µg·kg-1 to 1399.4 µg·kg-1 (dry weight) with an arithmetic mean concentration of 119.4 µg·kg-1. The characteristics of PAHs showed that 4- to 6-ring PAHs were slightly dominant in this study area, and most of the PAHs were significantly correlated (P<0.01), which indicates that the sources of the PAHs had some similarities in this sampling area. Source apportionment results derived from two different models were similar, indicating that the sources of PAHs were coal combustion, biomass combustion, fossil fuel combustion, and diesel combustion. The results of the PMF were more detailed, with the following four factors being identified:gasoline combustion (24.05%), diesel combustion (6.17%), low-temperature pyrolysis processes (60.67%), and coal combustion (9.11%).

[Expression of matrix metalloproteinase-2, -9 and their inhibitor-1 in hypertrophic scars].

OBJECTIVE: To investigate the gene expression of matrix metalloproteinases (MMP-2, MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in proliferative and mature hypertrophic scars. METHODS: Total RNA from 8 normal skin samples and from 16 human hypertrophic scar samples of different maturing stage was respectively extracted, and then mRNA was isolated. The gene expressions of MMP-2, MMP-9 and TIMP-1 in these samples were examined with reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The gray scale ratio of MMP-2, MMP-9 and TIMP-1 transcription in normal skin were (3.8 +/- 0.7)%, (5.8 +/-4.4)%, (30.3 +/- 3.0)%, respectively, which were obviously higher than those in proliferative hypertrophic scar [(14 +/- 5)%, (18 +/- 5)%, (38 +/- 4)%, P < 0.05]. The expression of MMP-2 and MMP-9 genes in mature hypotrophic scar returned to normal level, but that of TIMP-1 remained high when compared with that of normal level (P < 0. 05). CONCLUSION: The increase in MMP-2, MMP-9 and TIMP-1 gene expression might be involved in the formation of hypertrophic scars, while the lowering of MMP-2 and MMP-9 gene expression might be associated with the maturation of hypertrophic scars.

[Isolation, culture and identification of adult epidermal stem cell].

OBJECTIVE: To explore and establish a new method of isolation, culture, and identification of adult epidermal stem cell in vitro for the provision of seed-cells in tissue engineering of skin. METHODS: Epidermis was obtained by digesting human foreskin with protease and it was dissociated into single cells with trypsin and ethylenediaminetetraacetic acid (EDTA). These single epidermis cells were inoculated onto human collagen IV coated flasks and cultured at 37 degrees C in a humidified atmosphere containing 5% CO(2). The nonadherent cells were rinsed off 10-15 minutes after inoculation. The adherent cells were observed under phase contrast microscope and electron microscope, and they were identified with immunocytochemical methods. Cell cycles of the adherent cells were determined with flow cytometry. RESULTS: With phase contrast microscope, the rapidly adherent cells were observed to form colonies 24 hours after inoculation. Immunocytochemistry showed the rapidly adherent cells were positive for beta1-integrin and keratin 19. Cell cycles showed that about 86.83% cells were in resting state/pre-DNA-synthetic gap (G0/G1 phase). Electron microscopy revealed that the rapidly adherent cells were immature. CONCLUSION: This study shows that adult epidermal stem cells could be isolated and cultured in vitro successfully.

[The effect of hyperoxic Ringer's solution on the rabbits with inhalation injury at early postburn stage].

OBJECTIVE: To investigate the effect of hyperoxic Ringer's solution on inhalation injury given at early postburn stage in rabbit. METHODS: Seventy-seven rabbits were randomly divided into four groups, i.e. A (normal control, n = 5, without injury), B (n = 24, with Ringer's solution infusion for 10 days after injury), C (n = 24, with hyperoxic Ringer's solution infusion for 10 days after injury) and D (n = 24, without treatment after injury) groups. The rabbits in B, C and D groups were observed on 1 post injury day (PID), 2 PID, 3 PID, 5 PID, 7 PID and 10 PID, with 4 in each time points. The vital signs and survival rate were observed and the blood gas analysis, the WBC and PMN in the peripheral blood, ratio of wet/dry weight (W/D) of the lung tissue, the MDA, SOD contents in the pulmonary tissue, and the pulmonary pathomorphology were determined by corresponding methods. RESULTS: The respiratory rate of the rabbits increased postburn, which was accompanied with gasping breath, flapping of nasal alae, frequent cough, and increased buccal and nasal secretion. Dry and wet rales were heard in the lungs after injury. The survival rate in D, B and C groups was 13.3%, 27.8% and 65.6%, respectively. Metabolic acidosis was identified in these groups by blood gas analysis. The indices of PaCO2, WBC, PMN, W/D, MDA in B, C and D groups were higher than those in A group in the order of D > B > C > A groups. While the pH, PaO2 value and SOD content in D group were lower than those in A group in the order of D < B < C < A groups (P < 0.05). Pathomorphological examination revealed that pulmonary volume increased after the injury with microscopic inflammatory changes in pulmonary tissue in B, C and D groups. While the extent and degree of injury in C group after the treatment of hyperoxic Ringer's solution were evidently less severe than those in other groups. CONCLUSION: Early administration of hyperoxic Ringer's solution during the early postburn stage could be beneficial to the management of inhalation injury.