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Focal adhesion kinase (FAK) activation has been reported to be associated with cell progression and metastasis in a wide variety of cancer cells. Target treatment by inhibiting FAK has achieved remarkable effects in several cancers, but the effect in ovarian cancer has not been reported. In this study, we determined the role and the underlying molecular mechanism of BI853520, a novel small chemical FAK inhibitor against ovarian cancer. Results show that phosphorylated FAK tyrosine 397 (p-FAK Y397) is highly expressed in ovarian cancer tumor tissues and cell lines (SKOV3 and OVCAR3). BI853520 treatment greatly suppresses cell proliferation, viability, migration, invasion, decreases anchorage-independent growth and motility in vitro. Besides, treatment with BI853520 increases biologic effects following combination with chemotherapy in ovarian cancer cell lines. In addition, BI853520 suppresses EMT in ovarian cancer cell lines. Mechanically, BI853520 treatment downregulates the activation of PI3K/AKT/mTOR signal pathway. Finally, mice model experiments confirm BI853520 treatment dramatically reduces tumor growth in vivo and suppresses the activation of PI3K/AKT/mTOR signal pathway. Taken together, our findings demonstrate that focal adhesion kinase inhibitor BI853520 inhibits cell proliferation, migration, invasion and EMT process through PI3K/AKT/mTOR signaling pathway in ovarian cancer, and BI853520 can offer a preclinical rationale for targeting repression of FAK in ovarian cancer.

A facile template-free solvothermal method without any additional alkali was developed to fabricate a 3D hierarchical hollow microsphere precursor, followed by annealing in air, leading to a novel 3D hierarchical NiCo2O4 hollow microsphere material, which is composed of mesoporous (16.1 nm) ultrathin nanosheets (∼11–21 nm) consisting of ultrafine NiCo2O4 nanoparticles (11.9 nm). This 3D hierarchical NiCo2O4 nanosheet hollow microsphere material possesses a high specific surface area (93.4 m2 g−1) and mesoporosity, and thus superior electrochemical performance as an advanced electrode material. For methanol electrooxidation, the 3D hierarchical NiCo2O4 nanosheet hollow microsphere displays much higher electrocatalytic activity (95 A g−1, at 0.6 V), lower overpotential (0.27 V, vs. SCE), and higher stability compared with the 3D hierarchical NiCo2O4 nanosheet solid microspheres, Co3O4 and NiO microspheres. For supercapacitors, the NiCo2O4 hollow microsphere exhibits excellent specific capacitance of 1701 F g−1 at 1 A g−1, excellent rate capability (61.5% retention at 15 A g−1), and good electrochemical stability with 78.2% retention after 1000 charge–discharge cycles even at a high current density of 10 A g−1. These findings can be explained by the unique integral characteristics of 3D NiCo2O4 hollow spheres with high electron conductivity, large surface area and numerous open spaces between neighboring mesoporous ultrathin nanosheets, which can offer many facile diffusion paths for ion/electrolyte and greatly improve the electron/ion transfer within the electrode and at the electrode–electrolyte interfaces.

In video transmission, the compressed signal is extremely vulnerable to bit errors. Error concealment is widely used in video decoder to recover corrupted frames. Due to the use of variable length codes (VLCs), a single bit error in block-based bitstream may propagate to following of this slice. Especially, the effectiveness of error concealment technique relies heavily on correctly locating errors. In this paper, an error detector based on syntax and continuity which consists of two stages is proposed. The first stage is to find erroneous slice according to checking constraints imposed on video bitstream syntax or detecting special error patterns. In the second stage, the precise position of the first erroneous macroblock (MB) is found based on the continuity of spatial or temporal data of neighbor MBs. Simulation results demonstrate that the proposed method improves performance of error detection significantly compared with the traditional syntax-based method.

In this paper the operation characteristics of a novel picosecond pulse source is investigated experimentally and simulated numerically. The stable and pedestal-free pulse source is consisted of an electroabsorption modulator (EAM) and the following well-designed fiber-based pulse compressor. The obtained pulse has width of less than 2.5 ps, high extinction ratio, low timing jitter even in a large pump power range of around 2.4 dB. The basic function and characteristics of every component in the compressor is investigated in detail. The experimental results are in complete agreement with the simulation results. Finally, as an application illustration of the obtained pulse source, the obtained pulse train is applied to 16 × 10 Gbit/s optical time-division multiplexing (OTDM) system successfully.

A novel optical switch featured with high repetition rate, short switching window width, and high contrast ratio is proposed and demonstrated for the first time by placing an electroabsorption modulator (EAM) in a terahertz optical asymmetric demultiplexer (TOAD) configuration. The feasibility and main characteristics of the switch are investigated by numerical simulations and experiments. With this EAM-based TOAD, an error-free return-to-zero signal wavelength conversion with 0.62 dB power penalty at 20 Gbit/s is demonstrated.

A 40 Gbit/s optical 3R regenerator is proposed and demonstrated. The 3R regenerator consists of a dual-ring injection mode-locked fiber ring laser as the clock recovery module and an electroabsorption modulator (EAM) as the decision gate. The clock recovery module extracts the optical short pulse clock with low timing jitter from degraded 40 Gbit/s optical data streams, while the decision gate restores their signal quality. A numerical model describing the cross-absorption modulation effect in a bulk EAM is developed to explore the operating conditions, such as bias voltage, pump signal power. The timing jitter tolerance for the EAM optical gate is also investigated. Significantly improvement of BER is obtained from 40 Gbit/s RZ signals which are degraded by polarization mode dispersion or chromatic dispersion.

A 40-Gb/s 3R regenerator with a two-ring injection mode-locked fiber laser as the clock recovery and an electroabsorption modulator (EAM) as the reshaping optical decision gate is proposed and demonstrated. The cross-absorption modulation effect in a bulk EAM was also numerically modeled. Using this model, both the shape and the extinction ratio of the optical decision gate are optimized. The model is also employed to investigate the tolerance of the timing jitter, the chromatic dispersion, and the polarization mode dispersion of an all-optical 3R regenerator based on a bulk EAM decision gate. The operation margin of the 3R regenerator is presented. The theoretical results agree well with the experimental results

In this paper, NRZ format wavelength conversion using cross absorption modulation (XAM) in InGaAsP MQW electroabsorption modulator (EAM) is investigated experimentally in detail for the first time, to the best of our knowledge. The influence of two key operating parameters, input signal power and bias voltage of EAM, on wavelength conversion performance is studied. Experimental results indicate that there exists optimal bias voltage for fixed input signal power and that there exists also optimal input signal power for fixed bias voltage and the lowest power penalty of 0.9 dB is obtained by optimizing these two parameters. The physical explanations are given for these results based on operating characteristic of EAM device. Finally, the probe light wavelength dependence of wavelength conversion is studied for span of 1530–1560 nm.

The performance of a multiwavelength continuous-wave (CW) optical source based on a supercontinuum (SC) has been numerically studied in a 10 Gb s−1 dense wavelength division multiplexed transmission system. The Q factor is calculated as a measure of the system performance. Effects of the bandwidth of the arrayed-waveguide-grating filter, the transmission fibre input power, and the SC spectral flatness on the Q factors are presented. A multichannel equalization filter is used to improve the performance of the multiwavelength CW optical source and good results are obtained. A comparative study of different modulation formats, non-return-to-zero and return-to-zero, is also performed to evaluate their tolerance to linear and nonlinear impairments.

All optical bit clock recovery is one of the key technologies for all optical 3R recovery. In this paper, a simple method applying the combination of Fabry–Perot (F–P) filter and semiconductor optical amplifier (SOA) for clock recovery is proposed. The effect of the F–P filter finesse on the clock recovery and the reduction in the amplitude fluctuation of the clock pulse by the SOA are discussed theoretically. With this technology 10 Gbit / s clock recovery with equal amplitude and wavelength transparency was realized experimentally.

In the design of comb-like dispersion-profiled fiber (CDPF) for pulse compression, the length of the dispersion shift fiber (DSF) is determined by the nonlinear phase shift of each segment. To achieve a higher compression factor, it is necessary to increase the phase shift experienced by the pulse in each segment. However, a too large phase shift generally results in severe pulse distortion or breakup and the shedding of a large proportion of the pulse energy to a dispersive background level. Pulse-compression experiments are made with three different CDPFs of different nonlinear phase shifts and a high-quality compression effect is achieved. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 401–404, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11230

Optical clock division and multiplication were realized with an injection mode-locked fiber ring laser based on semiconductor optical amplifier SOA owing to the relatively long recovery time of carriers in SOA and the rational harmonic mode-locking. Second frequency division and 1.5th frequency multiplication of 10 GHz , second and 3 4 th frequency division of 20 GHz optical pulse trains were realized, respectively, in the experiment.

Supercontinuum (SC) pumped by a 10-GHz active mode-locked Er3+-doped fiber-ring laser (AML-EDFL) has been gained and the characteristics of the optical pulses extracted from SC have been studied. The central wavelength, bandwidth, and shape of the filters will have important effects on the optical pulses' output. Some conclusions about the filters are drawn from using SC as the optical source for a wavelength-division multiplexing over optical-time-division multiplexing (WDM/OTDM) transmission system. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 387–390, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10926

Clock recovery from degraded signals at 10, 20, and 40 Gb/s data rates was achieved using a two-ring injection mode-locked fiber-ring laser based on 10-GHz bandwidth components. No pattern effect was observed in these experiments. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 273–276, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10892

A novel clock recovery scheme using two-ring injection mode-locked fiber ring laser based on all 10 GHz bandwidth components was demonstrated. With this scheme, the clock with low timing jitter was obtained from a degraded 10 Gb/s optical data stream. Optical clock recovery was also achieved from a degraded 20 Gb/s optical data train when the clock division technique in the opto-electronic oscillator (OEO) and the rational harmonic mode-locking technique in the fiber ring laser were applied. No pattern effect was observed in the experiments.

A novel method was suggested about pedestal reduction and chirp elimination of high-order compressed solitons by using SOA and tunable filter. Results of numerical simulation demonstrate that, under certain conditions, the pedestals and chirp can be successfully mitigated without pulse broadening.

The reason of pulse amplitude unequalization at repetition rate multiplying via Fabry-Perot (F-P) filter is analyzed. Several original methods of suppressing the amplitude unequalization are proposed. Their suppressing effects and tolerance to the F-P instability are compared and investigated.

A theoretical assessment of the interferometric noise in the optical time division multiplexing (OTDM) transmission system is presented. The impact of such noise on the system performance were investigated in detail. The corresponding system requirements were also revealed by the calculation results. Recommendations on the use of prechirping to reduce the interferometric noise in the OTDM system are given.

A theoretical study of active mode-locking fiber loop laser using semiconductor optical amplifier (SOA) was presented in this paper. The effects of linewidth broadening factor of SOA on active mode-locking were investigated originally. The relations between parameters of output pulse series and the critical parameters of SOA and other elements in fiber loop were obtained.

A 10-GHz fiber-integrated ring laser incorporating a semiconductor optical amplifier and an electroabsorption modulator was investigated both theoretically and experimentally. The time-domain ABCD law was employed to clarify the impacts of optical elements on the mode-locked pulses. The obtained analytical results were testified by the experimental ones. Such a ring laser also showed good performance as an optical pulse source, which generated a stable pulse train with a pulse width of 10 ps and a tunable wavelength range of 30 nm.

A simple technique, based on nonlinear polarization rotation, for the amplitude equalization of high repetition rate pulses generated from a rational harmonic mode-locked fiber ring laser was demonstrated. Amplitude equalized pulses at 10 GHz (the fourth rational harmonic) were obtained with a harmonic component suppression ratio up to 30 dB. A theoretical explanation was given in detail, which indicates that, after pulse amplitude equalization, the situation of unequal pulse spacing can be improved to a certain extend.

A time-interweaved sampling scheme for optical A/D conversion is proposed, and to demonstrate this technique 2.5 GHz sine microwave signal is sampled at a rate of 16×2.5 GHz. 29dB signal-to-noise rate is acquired after processing the experimental data. In this paper we analyse the impacts of the imperfect optical sampling pulses, including the waveform, pulse width, and time jitter, and then discuss the way to improve the sampling precision.

Detuning characteristics of the AM mode-locked fiber laser are studied both in analytic theory and numeric simulation. The analytic expression of the locking range is given and is additionally verified by the numeric study. Both the two theories reveal that the pulse width remains as a constant and the pulse position varies linearly versus the detuning, when the detuning is small enough. The laser characteristics both inside and outside the locking range are examined in detail.

In this letter, a dispersion imbalanced loop mirror (DILM) was constructed by the use of one segment of high dispersion fiber and another segment of much lower dispersion. Based on the nonlinear switching properties of the DILM, a 10 GHz actively and passively mode locked fiber laser was demonstrated for the first time to our knowledge. In this laser, the DILM was acted as not only a passive element to make further compression of the pulse but also an in-band ASE filter to increase the stability of the laser. Optical pulses possessing narrow pulse width (3.1 ps) and low timing jitter (400 fs) were generated successfully.

A novel configuration was demonstrated to realize dual-wavelength operation in an erbium-doped fiber ring laser by incorporating a pair of multiplexer/demultiplexer. The repetition rate of each channel can be separately changed by adjusting a delay line associated with that channel in the cavity without changing the radio frequency. Dual-wavelength pulses at 2.5 and 5 GHz respectively were simultaneously obtained with pulse widths of 17.7 and 13 ps.

The performance of optical time division multiplexing (OTDM) system is limited by a complex combination of noise. In this paper we present a theoretical framework for the optical receiver in OTDM system based on the moment generation function. The proposed receiver model is showed to be more accurate in predicting the bit error rate (BER) performance than the former ones. Its validity is also verified by the experimental results.

Pulse compression and pedestal suppression can be realized simultaneously by employing an unbalanced nonlinear optical loop mirror (NOLM). Only if the optimal conditions of soliton compression for the pulse with high initial power in the NOLM are satisfied and the asymmetrical attenuation in the NOLM is optimized can the transform-limited and pedestal-free narrow pulse be obtained. Utilizing this technique, nearly transform-limited and pedestal-free ∼3 ps pulses with 2.5 GHz repetition rate were obtained experimentally. The experimental results verified the optimization criteria of the NOLM compressor.

Some characteristics of supercontinuum generation in the dispersion-shifted-fiber are studied both in theory and experiment. The theoretical research shows how the fiber nonlinearities, such as self-phase-modulation, four-wave-mixing and cross-phase-modulation, play their roles in the supercontinuum generation. Some dependent parameters of supercontinuum generation, such as the fiber length, the pump power are also discussed in this paper. The experimental results agree well with the theoretical simulations.

In this paper, the theoretical model of the UNI is proposed in detail, which counts on the ultrafast nonlinearities and longitudinal effects of semiconductor optical amplifier (SOA). The transfer function of UNI is also obtained. The switching window, which is a key parameter for demultiplexer, is then analyzed. It's shown that the switching window properties are determined by the length of SOA, the length of the birefringence fiber (BRF), and the parameters of control pulses such as control pulse energy, pulsewidth, power.

In this paper, the properties of the demultiplexing module using the serialized nonlinear optical loop mirrors have been investigated. The noise of the demultiplexing output has been discussed in detail. The influences of the switches' settings on the noise and the properties of the bit error rate of each demultiplexing channel have also been investigated. It is shown that the power penalty of the demultiplexing module in a serial structure using the nonlinear optical loop mirrors is much lower than that in the parallel structure and it will be very small if the settings of the loop mirrors are carefully chosen

The time-domain ABCD matrix formalism is based on the propagation of a Gaussian pulse which is characterized by the pulsewidth and chirp. In this paper, we will perfect this method and derive time-domain ABCD matrices for more optical devices. Especially, we extend this perfected theory to analyze the principle of passive mode-locking by reasonable approximation though, as we know, the output pulse generated from passive mode-locking fiber laser is of sech-shape. It is attractive because it can present a fairly apparent view to understand the mechanism of fiber lasers as well as analytic results to understand the pulse characteristics.

Without any stabilization equipment, multiwavelength laser oscillation was obtained in Erbium-doped fiber laser, basing on a section of standard multimode optical fiber which was twined as a polarization controller (PC). The number of lasing wavelength and wavelength spaces can be controlled by changing the state of PC.

In this paper, the properties of the optical phase-locked loop(PLL) based on the four-wave mixing in the semiconductor laser amplifiers (SLAs) are discussed. The components that achieve the function of detecting the bit phase of the input optical signal are concerned and discussed in detail together as a function module named as the optical bit phase detector referred to the general electronic PLL. Therefore, most of the properties of the optical PLL can be analyzed by applying the general phase-locked theory. Here the stability of the optical PLL is discussed. It's shown that the variance of input signal power in the practical application will cause optical PLL system unstable because of its long loop delay. The influence on the output phase jitter of the optical PLL is also investigated.

A clock extraction scheme was demonstrated using an optoelectronic oscillator from high-speed nonreturn-to-zero (NRZ) signal. A theoretical model on the locking range of the oscillator was presented. A 10-GHz clock with a timing jitter of 0.4 ps was extracted from 10-Gb/s NRZ signal and a locking range of 800 kHz was achieved. NRZ to return-to-zero (RZ) data format conversion was also performed simultaneously with the NRZ clock extraction.

A novel approach is proposed to reduce the amplitude fluctuation and timing jitter of clock pulses recovered from an injection mode-locked laser based on the semiconductor optical amplifier (SOA) caused by the pattern effect. A comb-like filter is used to preprocess the data pulses that are then injected into the injection mode-locked laser to recovery the clock. Numerical calculation for 40-Gb/s clock recovery demonstrates that this method is very effective for high-speed clock recovery based on the SOA.

The effect of filter characteristics on the output performance of actively mode-locked fiber ring lasers has been studied experimentally and numerically, with the same 3-dB bandwidth, the filter that has a flatter wavelength response tends to generate narrower soliton-like pulses.

The switching performance of the semiconductor laser amplifier in a loop mirror (SLALOM) with a polarization-independent multiquantum-well SLA influenced by the carrier transport is discussed. It is shown that the switching window is polarization-dependent in the case of ultra-short pulses used as switching pulses because of the carrier transport effect between quantum wells. The influence of polarization can be suppressed by modifying the polarization state of local switching pulses.

The q-parameter and the ABCD law are useful tools for analyzing the propagation or oscillation behavior of the spatial Gaussian laser beam. In this letter, we apply these tools to the theory of the actively mode-locked Er/sup 3+/-doped fiber laser (AML-EDFL). Based on the q-parameter definition, we derive the ABCD matrices for the four primary elements which influence the pulse forming in the AML-EDFL, including the amplitude modulator, the optical filter, the fiber with dispersion, and the fiber with nonlinearity. With the aid of the split-step q-parameter processing algorithm, the laser characteristics versus some typical laser parameters are investigated in detail.

Whole-frame loss of the compressed video is very common in transmission over error-prone networks since each coded picture is usually packetized into one single packet in order to reduce the bitstream overhead for transmission. In this paper we present an adaptive frame recovery algorithm which innovatively introduces the three-dimensional recursive search (3DRS) motion estimation method into fram reovr (FR), and dynamically selects between 3DRS based recovery and motion vector copy (MVC) based recovery according to the statistics of motion activity of previous frames. If the motion activity of the frame is large, we adopt 3DRS-based frame recovery. Otherwise MVC-based FR is used. For the former method, we first perform the modfief 3DRS to re-estimate the motion vectors (MVs) of the previous frame considering that the available motion information of previous frames is not close to the true motion trajectory. Then the MVs are extrapolated and refined as the MVs of the lost frame. The missing frame is recovered using motion compensation. For MVC-based FR, motion information of previous frames, derived from the decoder is reused. Experimental results show that our proposed solutions can achieve significant improvements in both PSNR and visual quality.

This paper presents a spatial error concealment technique using "verge points" which are the high-curvature points on image surfaces. Associated with curvature information, the verge points provide important characteristics in reconstructing broken edges. In our method, only a single layer of verge points surrounding the missing area are extracted. The broken edges are reconstructed by pairing these verge points with respect to both the curvature information and their neighboring pixel values. Simulations show that with our pairing criterion, most of the object edges are recovered and our concealment technique yields satisfactory results especially in terms of subjective perception.

We present an object geometry based error resilience method. We extract object geometry through analyzing motion vector field at the encoder using the iterative self-organizing data analysis technique algorithm. The extracted object geometry, in the form of an index map, is then embedded in the bitstream. At the decoder side, this information is exploited to recover motion vectors of corrupted macroblocks. The proposed method has been validated in MPEG2 codec in a standard-compliant way. Experimental results carried out on several sequences have shown that the proposed method outperforms two conventional temporal error concealment methods by an average PSNR gain of 0.9 dB and 1.5 dB, respectively.

We propose a simple and stable pulse compression scheme based on a filtering self-phase modulation broadened spectrum in a highly nonlinear fiber. It is found experimentally that under offset filtering the compressed pulse has a better quality compared with center filtering, such as a no pulse pedestal. Furthermore, numerical simulations reveal that the scheme has the potential to improve the pulse extinction ratio during compression. Finally, based on the obtained pulse train the 4 × 10 Gbits/s optical time-division multiplexing system is studied for verification of the high pulse quality. The compression scheme has the advantages of simple configuration, being pedestal-free, and having a high pulse extinction ratio.