Enhanced anti-tumor immunity ex vivo induced by GM-CSF gene transducted dendritic cell vaccine

Objective： The aim of the study was to investigate whether dendritic cell （DC） precursors, recruited by injection of chemokine ligand 3 （CCL3）, induce enhanced anti-tumor immunity after granulocyte-macrophage colony stimulating factor （GM-CSF） transfection in mice ex vivo. Methods： The 615 mice were injected with CCL3 via the tail vein. Freshly isolated B220–CD11c＋ cells were cultured with cytokines. For adenoviral （Ad）-mediated gene transduction, DCs were transferred AdGM-CSF gene at different ratios of multiplicity of infection （MOI） to determine the optimal gene transfection conditions, and detecting the expression of GM-CSF after transfection. The variation of GM-CSF gene-modified DCs were analyzed by morphological observation, phenotype analysis, and mixed lymphocyte reaction （MLR）. DCs were loaded with gastric cancer antigen obtained by frozen and thawed method. The stimulated DCs vaccination induced T lymphocytes, and the killing effect of T cells to gastric cancer cells was assayed by MTT. INF-γ production was determined with the INF-γ ELISA kit. Results： B220–CD11c＋ cells numbers increased after CCL3 injection. ELISA results showed that after GM-CSF gene modification, DC could produce high level of GM-CSF. When DCs were transferred AdGM-CSF gene at MOI equal to 1：100, GM-CSF level in culture supernatants reached saturation [（130.00 ± 12.61） pg/mL]. After GM-CSF gene-modification, DCs tended to more maturated through morphological observation and were phenotypically identical to typical DC and gained the capacity to stimulate allogeneic T cells. T lymphocytes stimulated with DC transduced with GM-CSF gene showed the specific killing effect on gastric carcinoma cells and produced high level of INF-γ [（1245.00 ± 13.75） pg/mL]. Conclusion： CCL3-recruited DCs modified by adenovirus-transducted GM-CSF could produce high level of GM-CSF, which tended to more maturated, and the capacity of activating allogeneic T lymphocytes proliferation was enhanced greatly. Moreover, they could stimulate specific cytotoxic T lymphocyte （CTL） to gastric cancer ex vivo.

Fabrication of amorphous nanoporous ZrO_(2)/SiO_(2) aerogel enabling nonlinear optical properties

Amorphous oxides have unique physicochemical properties with extensive opto-electronic applications such as the thin-film transistor,light-emitting diode backplanes,and supercontinuum generation.In this contribution,we synthesize the amorphous ZrO_(2)/SiO_(2) nanoporous aerogel with high structural integrity.With the femtosecond excitation laser at 800–1,064 nm,the broadband second harmonic generation is observed.The nonlinear optical properties of the as-prepared ZrO_(2)/SiO_(2) aerogel are investigated at 1.0μm and 1.5μm for the first time.Subsequently,the amorphous ZrO_(2)/SiO_(2) saturable absorber is originally applied in the Yb-doped and Er-doped fiber lasers to realize the mode-locking operations.In the Yb-doped fiber laser,the dissipative soliton resonance mode-locking operation is demonstrated with the largest pulse duration of 22 ns at a repetition rate of 7.8 MHz and a high signal-to-noise ratio of 64 dB.In the Er-doped fiber laser,a conventional soliton mod-locking regime is observed with an ultrashort pulse width of 960 fs,a repetition frequency of 6.55 MHz,and a time-bandwidth production of 0.347.Our work shows the good ability of the ZrO_(2)/SiO_(2) aerogel in generating ultrafast pulses and extends the saturable absorber into the amorphous material realm.

Bismuthene quantum dots integrated D-shaped fiber as saturable absorber for multi-type soliton fiber lasers

In the present work,the uniformly sized bismuthene quantum dots(BiQDs)with an average diameter of 26 nm were fabricated via the solvothermal approach.By transferring the BiQDs onto the plane of micro-machined D-shaped fiber(DSF),a new type of saturable absorber(SA)was successfully prepared.Based on the evanescent field effect of D-shaped fiber,the prepared SA exhibits excellent saturable absorption properties with the maximum modulation depth of 5.1%at around 1.5μm.To further investigate its potential applications in ultrafast photonics,we demonstrated passive mode-locking operation in the erbium-doped fiber laser(EDFL)with BiQDs/DSF-SA.The conventional soliton pulses with duration of 835 fs at the repetition rate of 9.23 MHz and dissipative soliton pulses with duration of 575 fs at the repetition rate of 7.83 MHz were generated successfully.In addition,stable bound state of solitons with the pulse duration of 1.04 ps and sub-pulse time interval of 15.9 ps were also obtained based on the conventional soliton state by adjusting the pump power and polarization state.Our work reveals the great potential and capacity of BiQDs/DSF-SA in soliton mode-locking operations and promotes the explorative investigation of bismuth-based optoelectronic devices.

Nonlinear optical properties of carboxyl-functionalized graphene oxide for dissipative soliton resonance pulse generation

Here,we investigated the nonlinear optical(NLO)characteristics of carboxyl-functionalized graphene oxide(GO-COOH)in the near-infrared(NIR)region.The results revealed that GO-COOH samples exhibit strong saturable absorption at low pump levels and a gradual transition to reverse saturable absorption(RSA)with increasing pump power.Then the saturable absorber(SA)by depositing the GO-COOH on the side-polished fiber(SPF)was employed in Yb-and Er-doped fiber lasers.Stable ultrashort pulses operating in the dissipative soliton(DS)and conventional soliton(CS)regimes were obtained with pulse widths of 26.6 ps and 968 fs,respectively.Besides,the dissipative soliton resonance(DSR)phenomenon caused by the RSA of GO-COOH was also observed with increasing pump power.The high-stable DSR mode-locked pulses with the maximum pulse energy of 1.91 nJ and 0.74 nJ were obtained in YDFL and EDFL respectively.These results not only reveal the potentiality of GO-COOH in ultrafast photonics applications but also open a new avenue to explore high-pulse-energy laser sources based on twodimensional materials.

High-quality 2-μm Q-switched pulsed solid-state lasers using spin-coating-coreduction approach synthesized Bi_2Te_3 topological insulators

In this paper, the fabrication process and characterization of Bi_2Te_3 topological insulators(TIs) synthesized by the spin-coating-coreduction approach(SCCA) is reported. With this approach, high-uniformity nano-crystalline TI saturable absorbers(TISAs) with large-area uniformity and controllable thickness are prepared. By employing these prepared TIs with different thicknesses as SAs in 2-μm solid-state Q-switched lasers, thickness-dependent output powers and pulse durations of the laser pulses are obtained, and the result also exhibits stability and reliability. The shortest pulse duration is as short as 233 ns, and the corresponding clock amplitude jitter is around 2.1%, which is the shortest pulse duration in Tl SA-based Q-switched 2-μm lasers to the best of our knowledge.Moreover, in comparison with the TISA synthesized by the ultrasound-assisted liquid phase exfoliation(UALPE)method, the experimental results show that lasers with SCCA synthesized TISAs have higher output powers, shorter pulse durations, and higher pulse peak powers. Our work suggests that the SCCA synthesized TISAs could be used as potential SAs in pulsed lasers.

Third-order nonlinear optical responses of CuO nanosheets for ultrafast pulse generation

As a representative transition metal oxide,cupric oxide(CuO)has attracted a lot of interest in miscel-laneous fields.In the present work,the prominent third-order nonlinear optical(NLO)features of CuO nanosheets were demonstrated via the typical Z-scan technique at 1 m m.The open-aperture(OA)Z-scan measurements at different intensities clearly showed that CuO nanosheets possessed the saturable ab-sorption(SA),reverse saturable absorption(RSA)and optical limiting behaviors.The closed-aperture(CA)Z-scan technology was implanted to investigate the nonlinear refractive index and the third-order nonlinear susceptibility.In virtue of the strong nonlinear optical absorption properties of CuO nano-sheets,a stable all-solid-state mode-locked laser with the as-prepared CuO nanosheets as saturable absorber at 1.06 m m was realized for the first time.Our work confirmed that CuO nanosheets exhibited outstanding NLO properties,which might stimulate the development in ultrafast photonics and nonlinear optics.

Multilayer black phosphorus as saturable absorber for an Er:Lu_(2)O_(3) laser at~3 μm

Multilayer black phosphorus(BP) nanoplatelets of different thicknesses were prepared by the liquid phase exfoliation method and deposited onto yttrium aluminum garnet substrates to form saturable absorbers(SAs). These were characterized with respect to their thickness-dependent saturable absorption properties at 3 μm. The BP-SAs were employed in a passively Q-switched Er:Lu_2O_3 laser at 2.84 μm. By using BP exfoliated in different solvents,stable pulses as short as 359 ns were generated at an average output power of up to 755 m W. The repetition rate in the experiment was 107 k Hz, corresponding to a pulse energy of 7.1 μJ. These results prove that BP-SAs have a great potential for optical modulation in the mid-infrared range.

Enhanced Q-switching performance of magnetite nanoparticle via compositional engineering with Ti_(3)C_(2) MXene in the near infrared region

In this work,we reported a new strategy to improve the nonlinear saturable absorption performance of magnetite(Fe_(3)O_(4))nanoparticles(FONPs)via the compositional engineering with the Ti_(3)C_(2) MXene in the near-infrared(NIR)region.Based on the DFT simulation,the band structures and work function were significantly modified by the Ti_(3)C_(2) MXene doping.By using the open-aperture Z-scan technology,the nonlinear optical features of the FONPs@Ti_(3)C_(2) nanocomposite were significantly improved,showing the great potential as the saturable absorber in the pulsed laser.With the nanocomposite as the saturable absorber,the passively Q-switched Nd:GdVO4 lasers emitted much shorter pulse durations when compared with the pristine FONP saturable absorber.These findings indicated that FONPs@Ti_(3)C_(2) heterostructure was a promising saturable absorber for the short pulse generation in the NIR region.

Gold nanorods as saturable absorbers for the passively Q-switched Nd:LLF laser at 1.34 μm

Gold nanorods(GNRs) with two different aspect ratios were successfully utilized as saturable absorbers(SAs) in a passively Q-switched neodymium-doped lutetium lithium fluoride(Nd:LLF) laser emitting at 1.34 μm. Based on the GNRs with an aspect ratio of five, a maximum output power of 1.432 W was achieved, and the narrowest pulse width was 328 ns with a repetition rate of 200 kHz. But, in the case of the GNRs with the aspect ratio of eight, a maximum output power of 1.247 W was achieved, and the narrowest pulse width was 271 ns with a repetition rate of 218 kHz. Our experimental results reveal that the aspect ratios of GNRs have different saturable absorption effects at a specific wavelength. In other words, for passively Q-switched lasers at a given wavelength, we are able to select the most suitable GNRs as an SA by changing their aspect ratio.

VO_(x)/NaVO_(3) nanocomposite as a novel saturable absorber for passive Q-switching operation

We report VO_(x)/NaVO_(3) nanocomposite as a novel saturable absorber for the first time,to the best of our knowledge.The efficient nonlinear absorption coefficient and the modulation depth are determined by the Z-scan technology.As a saturable absorber,a passively Q-switched Nd-doped bulk laser at 1.34μm is demonstrated,producing the shortest pulse duration of 129 ns at a repetition rate of 274 kHz.In the passively Q-switched Tm:YLF laser with the prepared saturable absorber,the shortest pulse duration was 292 ns with a repetition rate of 155 kHz.Our work confirmed the saturable absorption in VO_(x)/NaVO_(3) for possible optical modulation in the near-infrared region.

Subnanosecond KTiOPO4 optical parametric oscillator intracavity pumped by a Kerr-lens, mode-locked YVO4/Nd:YVO4 laser coupled with an acousto-optic modulator

A Kerr-lens, mode-locked YVO4∕Nd:YVO4laser coupled with an acousto-optic modulator（AOM） Q-switching near1064 nm was employed to pump an intracavity KTi OPO4（KTP） optical parametric oscillator. A subnanosecond signal wave near 1572 nm with low repetition rate was realized. At an AOM repetition rate of 8 kHz, the maximum output power was 165 mW. The highest average pulse energy, the shortest duration, and the highest peak power of a mode-locking signal pulse were estimated to be ～10.3 μJ, ～120 ps, and ～82 kW, respectively.

High peak power subnanosecond pulse characteristics with different wall structured CNTs in a doubly QML Nd:Lu_(0.15)Y_(0.85)VO_4 laser

By simultaneously employing both an electro-optic modulator and carbon nanotube saturable absorber(CNT-SA)in a dual-loss modulator, a subnanosecond single mode-locking pulse underneath a Q-switched envelope with high peak power was generated from a doubly Q-switched and mode-locked(QML) Nd:Lu_(0.15)Y_(0.85)VO_4 laser at1.06 μm for the first time, to our knowledge. CNTs with different wall structures—single-walled CNTs(SWCNTs),double-walled CNTs(DWCNTs), and multi-walled CNTs(MWCNTs)—were used as SAs in the experiment to investigate the single mode-locking pulse characteristics. At pump power of 10.72 W, the maximum peak power of1.312 MW was obtained with the DWCNT.