Laser induced high temperature thermal-mechanical-oxygen coupling experimental system and method.

In this paper, a thermal-mechanical-oxidation coupling experimental system based on laser heating is developed, containing two modes of Gaussian and flat-top lasers, which has a series of advantages such as high temperature range, rapid heating rate, and convenient observation. The system adopts active illumination and an optical filter to solve the problem where it is difficult for traditional digital-image correlation technology to image clearly under laser heating. A biaxial mechanical test machine is used to simulate the complex load by applying biaxial tension or compression loads on the material. Combined with the radiation temperature measurement and controllable flow field device, the thermal-mechanical-oxygen coupling experiment of high temperature resistant materials under aerobic environment can be carried out. The maximum uniform heat flux output density is 27.2 kW/cm2, and the maximum Gaussian heat flux output density is 105 kW/cm2. The thermal-mechanical-oxygen coupling experimental system and method are of great significance to the development of new high temperature resistant materials and thermal barrier coatings.

200 µJ, 13 ns Er:ZBLAN mid-infrared fiber laser actively Q-switched by an electro-optic modulator.

We report, as far as we know for the first time, on a pulsed 2.7 µm Er:ZBLAN fiber laser Q-switched by an electro-optic modulator. The Q-switched operation was achieved with a repetition rate range of 100 Hz-50 kHz. Pulse energy of 205.7 µJ and pulse width down to 13.1 ns, yielding a peak power of 15.7 kW, were obtained at a repetition rate of 100 Hz. The linewidth of the output spectrum was as narrow as 0.4 nm. The pulse width and the pulse peak power, to the best of our knowledge, are currently the shortest and the highest in the 3-µm-band Q-switched fiber lasers, respectively.

Thermal modeling of high-power Yb-doped fiber lasers with irradiated active fibers.

With both radiation effects and thermal effects taken into consideration, a multiphysics thermal model concerning high-power Yb-doped fiber lasers operated with post-irradiated active fibers is established. Radiation-related parameters, including propagation losses, refractive indexes and lifetime, are considered. And, with the temperature profile of the active fiber, temperature-dependent parameters, including absorption and emission cross-sections, refractive indexes and lifetime, are updated every loop to simulate the output parameters. Simulation results show that radiation induces great changes to the thermal profiles of the active fiber. And severe performance degradation of high-power Yb-doped fiber lasers are recorded, featuring a remarkable drop in output power and an even steeper decline in the transverse mode instability threshold, which is a predominant limitation at high radiation doses. With a deposited radiation of 100 Gy, an output decline of about 50% and a mode instability threshold drop over 85% are observed. And it's shown that, with the exploited active fiber, it's hardly possible for the investigated fiber laser to generate stable single-mode output at kilowatt levels with accumulated radiation doses beyond 50 Gy. At low radiation doses within 20 Gy, to maintain safe and stable single-mode operation of the laser system, longer active fibers with lower absorption coefficients are preferred despite a small rollover of the output power.

Effects of LED Light Color and Intensity on Feather Pecking and Fear Responses of Layer Breeders in Natural Mating Colony Cages.

Natural mating colony cages for layer breeders have become commonplace for layer breeders in China. However, feather pecking (FP) and cannibalism are prominent in this system. The objective of this study was to investigate the effects of four light-emitting diode (LED) light colors (white: WL, red: RL, yellow-orange: YO, blue-green: BG) with two light intensities for each color, on FP, plumage condition, cannibalism, fear, and stress. A total of 32 identical cages were used for the eight treatments (four replicates for each treatment). For both light intensities, hens in RL had a lowest frequency of severe FP, whereas hens in WL had the highest frequency of severe FP. Hens in RL and BG had better plumage conditions than in WL and YO. Compared with RL and BG treatments, hens treated with WL and YO had a significantly longer tonic immobility (TI) duration. Hens treated with RL had a higher concentration of 5-hydroxytryptamine (5-HT), a lower concentration of corticosterone (CORT), and a lower heterophil to lymphocyte ratio than WL and YO. Furthermore, RL could significantly reduce mortality from cannibalism. Overall, hens treated with RL and low light intensity showed a lower frequency of severe FP, less damaged plumage, were less fearful, had lower physiological indicators of stress, and had reduced mortality from cannibalism. Transforming the light color to red or dimming the light could be regarded as an effective method to reduce the risk of FP and alleviate the fear responses of layer breeders.

Thoracoscopy resection of a giant solitary fibrous tumor with double pedicles and double blood supply: a case report.

BACKGROUND: Solitary fibrous tumors are rare tumors derived from the pleura. A tumor generally has only one pedicle. Video-assisted thoracoscopic surgery is generally used when a tumor is small (< 10 cm), and traditional open surgery is often used when a tumor is large. CASE PRESENTATION: We report a 49-year-old male patient with a space-occupying lesion in the right chest. Three-dimensional reconstruction showed that the blood supply to the tumor originated from the right lower pulmonary artery and vein. The patient was treated with minimally invasive surgery. Intraoperative exploration revealed that the tumor had two tumor pedicles, and each pedicle has an independent blood supply. The special bagging and extraction of the specimen were applied. The size of the specimen was 18 × 12 × 6 cm. Postoperative pathological examination revealed a solitary fibrous tumor. CONCLUSIONS: The solitary fibrous tumor with double pedicles and double blood supply is very rare, and it has not been reported before. Preoperative three-dimensional reconstruction plays an important role in understanding the blood supply to the tumor and the location of the tumor pedicles. After careful and comprehensive evaluation, endoscopic surgery can also be applied to the treatment of the larger fibroma (> 10 cm). The larger specimen can be extracted from the smaller incision by the "pulling carrot" method.

Watt-level passively Q-switched heavily Er(3+)-doped ZBLAN fiber laser with a semiconductor saturable absorber mirror.

A diode-cladding pumped mid-infrared passively Q-switched Er(3+)-doped ZBLAN fiber laser with an average output power of watt-level based on a semiconductor saturable absorber mirror (SESAM) is demonstrated. Stable pulse train was produced at a slope efficiency of 17.8% with respect to launched pump power. The maximum average power of 1.01 W at a repetition rate of 146.3 kHz was achieved with a corresponding pulse energy of 6.9 µJ, from which the maximum peak power was calculated to be 21.9 W. To the best of our knowledge, the average power and the peak power are the highest in 3 µm region passively Q-switched fiber lasers. The influence of gain fiber length on the operation regime of the fiber laser has been investigated in detail.

Super-flat supercontinuum generation from a Tm-doped fiber amplifier.

Super-flat supercontinua are generated from a double clad Tm-doped fiber amplifier. Two different laser configurations are investigated and compared. In the direct-output configuration, the long-wavelength edge of the supercontinuum spectra is extended to beyond 2.65 µm with a 10 dB bandwidth of 740 nm. In the passive pigtail configuration, the generated supercontinuum features excellent flatness with an intensity difference smaller than 1 dB in the wide central spectral range from 1.98 µm to 2.41 µm.

[Cilostazol inhibits proliferation and induces apoptosis in rat vascular smooth muscle cells through Rb-p53-p21 pathways].

OBJECTIVE: To explore the effects and related mechanisms of cilostazol on rat vascular smooth muscle cells (VSMCs)proliferation. METHODS: VSMCs were treated with DMEM (control) and various doses of cilostazol (1.0×10(-7), 2.5×10(-7), 5.0×10(-7), 7.5×10(-7) and 1.0×10(-6) mol/L) for 13 d (cell counting) or 72 h. Proliferation of VSMCs was investigated by cell-counting, MTT and flow cytometry analysis. Cell apoptosis was determined by TUNEL staining. mRNA and protein expressions of cell cycle regulatory proteins, such as Rb, p53 and p21 were detected by RT-PCR and Western blot, respectively. RESULTS: Cilostazol inhibited VSMCs proliferation and induced VSMCs arrest at G1 phase in a dose-dependent manner. High dose of cilostazol (7.5×10(-7) and 1.0×10(-6) mol/L) induced VSMCs apoptosis. p53 mRNA expression in 2.5×10(-7) mol/L to 7.5×10(-7) mol/L groups as well as 1.0×10(-6) mol/L group (3.22 ± 0.45 vs. 1.75 ± 0.32) and p53 protein expression in 7.5×10(-7) mol/L group and 1.0×10(-6) mol/L group (0.53 ± 0.11 vs. 0.18 ± 0.06) were significantly upregulated after 72 h culture (all P < 0.05 vs. control). Low dose of cilostazol (1.0×10(-7), 2.5×10(-7) and 5.0×10(-7) mol/L) significantly upregulated p21 mRNA expression compared to control group (1.86 ± 0.19, 2.20 ± 0.24 and 2.10 ± 0.18 vs. 1.210 ± 0.18, all P < 0.05). Similarly, Rb mRNA expression was significantly upregulated in 1.0×10(-7), 2.5×10(-7) and 5.0×10(-7) mol/L groups (0.89 ± 0.07 vs. 0.38 ± 0.04)compared with control group (all P < 0.05). However, high dose cilostazol (7.5×10(-7) and 1.0×10(-6) mol/L) significantly downregulated p21 mRNA expression (0.81 ± 0.09 vs. 1.21 ± 0.18, 0.36 ± 0.10 vs. 1.21 ± 0.18, all P < 0.05 vs. control) and Rb mRNA expression (0.12 ± 0.02 and 0.11 ± 0.02 vs. 0.38 ± 0.04, all P < 0.05 vs. control). p21 and Rb protein expressions also upregulated at low concentrations of cilostazol and downregulated at high concentrations of cilostazol. CONCLUSION: Cilostazol could inhibit the proliferation of rat VSMCs through modulating Rb-p53-p21 pathway and induce VSMCs apoptosis through upregulating p53.

[Effect of percutaneous coronary intervention timing and cilostazol use on left ventricular remodeling in patients with non-ST elevation myocardial infarction].

OBJECTIVE: To observe the dynamic changes of plasma matrix metalloproteinases (MMPs) and investigate the effect of early or delayed percutaneous coronary intervention (PCI) in the presence or absence cilostazol on left ventricle (LV) remodeling in patients with non-ST elevation myocardial infarction (NSTEMI). METHODS: One hundred and sixty-four patients undergoing PCI with NSTEMI were randomized to early PCI (PCI within 24 h) group or delayed PCI group (PCI after 36 h), and patients in both group were further assigned to cilostazol or no cilostazol group. Plasma MMP-2 and MMP-9 concentrations were measured at 2, 4 days and 2 and 4 weeks after PCI. Left ventricular end-diastolic volume (LVEDV), left ventricle ejection fraction (LVEF), left ventricle posterior wall (LVPW) and interventricular septum (IVS) were measured by echocardiography at baseline and 1 year after PCI. RESULTS: MMP-2 concentration at 2 weeks after PCI is higher than that at 2, 4 days and 4 weeks after PCI. MMP-9 concentration at 4 days is higher than that at 2 days, 2 weeks and 4 weeks after PCI. MMP-2 and MMP-9 were significantly lower in cilostazol group compared with that in non-cilostazol group at 4 days, 2 weeks and 4 weeks after NSTEMI (all P < 0.05). Changes of LVEDV and LVEF were significantly less in cilostazol group and early PCI group than that in no cilostazol group and delay PCI group (P < 0.05 or P < 0.01) at 1 year after NSTEMI. CONCLUSIONS: Early PCI and Cilostazol use are associated with less LV remodeling in patients with NSTEMI. Cilostazol attenuated LV remodeling possibly by reducing concentration of MMP-2 and MMP-9 after PCI.