[Killing effect of icotinib combined with CIK on human lung adenocarcinoma cells in vitro].

Objective: To explore the inhibitory effect of icotinib combined with cytokine induced killer (CIK) on various human lung adenocarcinoma cell lines in vitro. Methods: The inhibitory effect of icotinib alone or icotinib combined with CIK on HCC827 and A549 cells was detected by cell counting kit-8(CCK-8). The apoptosis was detected by flow cytometry via Annexin V/PI staining. The effect of icotinib on CIK phenotype was detected by flow cytometry. Results: The inhibitory rates of HCC827 cells treated with 1.5, 3, 6, 12 µmol/L icotinib were (5.64±0.05)%, (8.62±0.45)%, (14.57±0.65)% and (18.52±0.91)%, respectively. The inhibitory rates of A549 cells were (1.64±0.48)%, (2.09±0.28)%, (3.69±0.45)%, (4.41±0.58)%, respectively. At the same concentration, the inhibitory rate of HCC827 cells with icotinib treatment was significantly higher than that of A549 cells (P<0.05). When the effector/target ratio was 10∶1, 20∶1 or 40∶1, the inhibitory rates of HCC827 cells co-cultured with CIK were (15.17±2.33)%, (42.59±7.18)%, (62.59±8.95)%, respectively, and the inhibitory rates of A549 were(16.99±2.81)%, (46.31±1.89)%, (58.24±4.23)%, respectively. The inhibitory rate of HCC827 cells co-cultured with CIK was not significantly different from that of A549 cells at the same effector/target ratio (P(10∶1)=0.299, P(20∶1)=0.318, P(40∶1)=0.366). When the effector/target ratio of CIK combined with 6 µmol/L icotinib was 10∶1, 20∶1 or 40∶1, the inhibitory rates of HCC827 cells were (37.07±3.50)%, (76.03±6.55)%, (80.34±10.69)%, respectively, and the inhibitory rates of A549 cells were(25.72±1.41)%, (52.76±3.82)%, (62.26±1.94)%, respectively. The inhibitory rates of 6 µmol/L icotinib combined with CIK were significantly higher than those of icotinib group and CIK group alone at the same effector/target ratio (P<0.05), except for the effector/target ratio at 40︰1 on A549 cells (P=0.089). Moreover, all of the combination index (CI) of combined group were <1 (P<0.05). The apoptotic rates of HCC827 and A549 cells induced by icotinib combined with CIK were significantly higher than those of icotinib group and blank control group (P<0.05), especially the proportion of late apoptotic or necrotic cells.Increasing effector/target ratio of CIK contributed to stronger inhibition(P<0.05). The expressional rate of CIK phenotype with or without icotinib treatment was not significantly different from each other(P>0.05). Conclusions: EGFR mutant lung adenocarcinoma cells are more sensitive to icotinib, while the EGFR mutation status has no effect on the killing effect of CIK cells. icotinib combined with CIK has a synergistic effect on the inhibition of tumor growth, and icotinib has no any impact on the phenotype of CIK cells.

Output characteristics of actively Q-switched Ho:LuVO4 laser at room temperature.

A compact continuous wave (CW) and actively Q-switched (AQS) Ho:LuVO4 laser pumped by a 1.94 µm Tm: YAP laser is demonstrated. The performance of the laser was investigated by changing the output coupler. The maximum output power of 4.1 W at 2058.43 nm in CW regime is obtained at the maximum absorbed pump power of 12.3 W. The minimum pulse width of 29.3 ns was obtained at Pulse Repetition Frequency (PRF) of 20 kHz with the same output coupler corresponding to a peak power of 6.9 kW. The maximal output power is 4.1 W with center wavelength of 2058.43 nm at PRF of 40 kHz, corresponding to slope efficiency of 43.0% with respect to absorbed pump power. The M2 factors measured by the traveling knife-edge method are 1.04 in parallel a-axis and 1.08 in parallel c-axis with diffraction limited beam quality.

Doubly Q-switched Ho:LuAG laser with acoustic-optic modulator and Cr²âº:ZnS saturable absorber.

A doubly Q-switched (DQS) Ho:LuAG laser resonantly pumped by a 1.91-µm laser was first presented with an acoustic-optic modulator (AOM) and a Cr2+:ZnS saturable absorber. A comparison among the active Q-switched (AQS), passively Q-switched (PQS), and DQS laser performances was carried out. The maximum continuous wave (CW) output power of 6 W with the central wavelength of 2100.65 nm was obtained at an incident pump power of 35.2 W. Compared with CW laser, the AQS, PQS, and DQS lasers shared the same central wavelength of 2098.34 nm under the same incident pump power. The central wavelength of the AQS and DQS lasers remained constant with the change of AOM repetition frequency (RF). When the incident pump power was 35.2 W and the AOM RF was 15 kHz, the DQS Ho:LuAG laser at a maximum RF of 2.13 kHz achieved the maximum average output power of 4.95 W. At the AOM RF of 10 kHz, the DQS Ho:LuAG laser achieved the shortest pulse width of 40.4 ns with the highest peak power of 61.5 kW. At an incident pump power of 35.2 W, the PQS Ho:LuAG laser obtained the shortest pulse width of 46.1 ns, corresponding to the RF of 2.25 kHz. Experiment results showed that the pulse width could be compressed effectively with a significant increase of peak power for a 2-µm DQS laser.

Resonantly pumped room temperature Ho:LuVO4 laser.

Spectroscopic characterization of a Ho:LuVO4 crystal grown by the Czochralski method has been performed, including the absorption and emission spectra. We demonstrate a 2 µm room temperature Ho:LuVO4 laser, resonantly pumped by a 1.94 µm Tm:YAP laser. By use of an output coupler with T=10% transmission, the Ho:LuVO4 laser generated continuous-wave output power of 2.5 W at 2074.18 nm, with a beam quality factor of Mx2=My2=1.3, for a total incident pump power of 19.4 W. The slope efficiency with respect to the pump power was 17.6%, and the optical-to-optical efficiency was 12.9%. Moreover, we obtained a Ho:LuVO4 laser that operated at 2073.77 and 2055.27 nm, by using different output couplers with transmissions of T=15 and 30%.

Field evidence for earlier leaf-out dates in alpine grassland on the eastern Tibetan Plateau from 1990 to 2006.

Worldwide, many plant species are experiencing an earlier onset of spring phenophases due to climate warming. Rapid recent temperature increases on the Tibetan Plateau (TP) have triggered changes in the spring phenology of the local vegetation. However, remote sensing studies of the land surface phenology have reached conflicting interpretations about green-up patterns observed on the TP since the mid-1990s. We investigated this issue using field phenological observations from 1990 to 2006, for 11 dominant plants on the TP at the levels of species, families (Gramineae-grasses and Cyperaceae-sedges) and vegetation communities (alpine meadow and alpine steppe). We found a significant trend of earlier leaf-out dates for one species (Koeleria cristata). The leaf-out dates of both Gramineae and Cyperaceae had advanced (the latter significantly, starting an average of 9 days later per year than the former), but the correlation between them was significant. The leaf-out dates of both vegetation communities also advanced, but the pattern was only significant in the alpine meadow. This study provides the first field evidence of advancement in spring leaf phenology on the TP and suggests that the phenology of the alpine steppe can differ from that of the alpine meadow. These findings will be useful for understanding ecosystem responses to climate change and for grassland management on the TP.

Efficient Q-switched Ho:GdVO4 laser resonantly pumped at 1942 nm.

An efficient 2 µm room-temperature Q-switched Ho:GdVO4 laser end-pumped by a 1942 nm Tm-fiber laser is demonstrated. To our knowledge, this is the first report of Q-switched performance of Ho:GdVO4 crystal. A maximum CW output power of 6.85 W under the absorbed pump power of 24.1 W was obtained with a slope efficiency of 39.5% at a temperature of 17°C. With the same absorbed pump power, a maximum output energy per pulse of about 0.9 mJ and minimum pulse width of 4.7 ns were obtained at the pulsed repetition frequency (PRF) of 5 kHz, corresponding to a peak power of approximately 187.2 kW.

Room temperature single longitudinal mode laser output at 1645 nm from a laser-diode pumped Er:YAG nonplanar ring oscillator.

We report on a monolithic 1645 nm Er:YAG nonplanar ring oscillator (NPRO) resonantly pumped by a fiber-coupled laser diode. In the experiment, an up to 550 mW single frequency laser output at 1645.2 nm was obtained, corresponding to a slope efficiency of 19.1% and an absolute efficiency of 6.0%. The beam quality M2 was measured to be 2.1 at the highest output power.

Single-frequency, Q-switched Ho:YAG laser at room temperature injection-seeded by two F-P etalons-restricted Tm, Ho:YAG laser.

We demonstrated a 1.91 µm pumped, injection-seeded Q-switched Ho:YAG laser operating at room temperature. By inserting two Fabry-Perot etalons into the laser cavity, single-frequency Tm, Ho:YAG seed lasing was achieved at a wavelength of 2090.9 nm, with a typical output power of 60 mW. Single-frequency, nearly transform-limited Q-switched operation of the Ho:YAG laser was achieved by injection seeding. The output energy of the single-frequency Q-switched pulse is 7.6 mJ, with a pulse width of 132 ns and a repetition rate of 100 Hz. We measured the pulse spectrum, half-width of which was 3.5 MHz, by a heterodyne technique.

Room temperature single-frequency output from a diode-pumped Tm,Ho:YAP laser.

Single-frequency operation in the range of 2102.45-2102.54 nm and 2130.72-2130.82 nm is demonstrated from a Tm,Ho:YAP laser at room temperature. To our knowledge, this is the first time a room temperature single-frequency Tm,Ho:YAP laser of up to 72.6 mW at 2102.5 nm with Fabry-Perot etalons has been obtained. Regulating the elevation angle of the two etalons, 42.0 mW at 2130.8 nm was obtained. The single-longitudinal-mode laser can be used as a seed laser for coherent wind measurements and differential absorption lidar systems.