Experimental study of quantum random number generator based on two independent lasers

Quantum random number generator (QRNG) can produce true randomness by utilizing the inherent probabilistic nature of quantum mechanics. Recently, the spontaneous-emission quantum phase noise of the laser has been widely deployed for QRNG, due to its high rate, low cost and the feasibility of chip-scale integration. Here, we perform a comprehensive experimental study of phase-noise based QRNG with two independent lasers, each of which operates in either continuous-wave (CW) or pulsed mode. We implement QRNGs by operating the two lasers in three configurations, namely CW+CW, CW+pulsed and pulsed+pulsed, and demonstrate their tradeoffs, strengths and weaknesses.Comment: 7pages,6figures.It has been accepted by PR

Hundred joules plasma focus device as a potential pulsed source for in vitro cancer cell irradiation

Indexación: Web of Science; Scopus.Plasma focus devices may arise as useful source to perform experiments aimed to study the effects of pulsed radiation on human cells in vitro. In the present work, a table top hundred joules plasma focus device, namely "PF-400J", was adapted to irradiate colorectal cancer cell line, DLD-1. For pulsed x-rays, the doses (energy absorbed per unit mass, measured in Gy) were measured using thermoluminescence detectors (TLD-100 dosimeters). The neutron fluence and the average energy were used to estimate the pulsed neutron doses. Fifty pulses of x-rays (0.12 Gy) and fifty pulses of neutrons (3.5 μGy) were used to irradiate the cancer cells. Irradiation-induced DNA damage and cell death were assessed at different time points after irradiation. Cell death was observed using pulsed neutron irradiation, at ultralow doses. Our results indicate that the PF-400J can be used for in vitro assessment of the effect of pulsed radiation in cancer cell research.http://recursosbiblioteca.unab.cl:2296/doi/pdf/10.1063/1.499465

Generation of pulsed dual wavelength erbium doped fiber laser

Single and dual wavelength fiber lasers and pulsed fiber lasers are well-known to be used for various applications. In the generation of dual wavelength fiber lasers and pulsed fiber lasers, the researchers found the mode competition among the dual wavelength is caused by the cross-gain saturation and strong homogeneous line broadening faced by erbium doped fiber (EDF). Therefore, the aim of this thesis is to generate a single and dual wavelength fiber laser and pulsed fiber laser by using fiber Bragg grating (FBG) in single ring and Figure-8 configurations at 1550 nm and 1560 nm. Analysis and optimization on single wavelength fiber laser and single wavelength pulsed fiber laser give a peak power of -10.70 dBm (8.51x10-2 mW) and -54.01 dBm (3.97x10-6 mW) with signal to noise ratio (SNR) of 59.70 dB and 10.29 dB, respectively, at 1550 nm. Similarly, at 1560 nm, this gives a peak power of -13.60 dBm (4.37x10-2 mW) and -60.00 dBm (1.00x10-6 mW) with SNR of 57.60 dB and 8.78 dB, respectively. For dual wavelength fiber laser and dual wavelength pulsed fiber laser, this gives a peak power of -12.90 dBm (5.13x10-2 mW) and -54.03 dBm (3.95x10-6 mW) at 1550 nm and a peak power of -14.80 dBm (3.24x10-2 mW) and -57.99 dBm (1.59x10-6 mW) at 1560 nm, respectively. The SNR obtained for 1550 nm and 1560 nm for dual wavelength fiber laser and dual wavelength pulsed fiber laser are 55.38 dB and 11.16 dB and 53.58 dB and 11.27 dB, respectively. The repetition rate of single and dual wavelength pulsed fiber laser is 2.878 MHz. It can be concluded that single and dual wavelength fiber lasers are successfully generated using single ring and figure-8 configurations whereas single and dual wavelength pulsed fiber laser are generated using only Figure-8 configuration due to mode locking occurrence. The polarization inside the cavity is controlled to solve mode competition and homogeneous in EDF, in order to obtain a stable dual wavelength

Episode-like pulse testosterone supplementation induces tumor senescence and growth arrest down-modulating androgen receptor through modulation of p-ERK1/2, pAR ser81 and CDK1 signaling: biological implications for men treated with testosterone replacement therapy

Despite the growing body of knowledge showing that testosterone (T) may not significantly affect tumor progression in hypogonadal patients treated for prostate cancer (Pca), the use of this hormone in this population still remains controversial. The effects of continuous or pulsed T stimulation were tested in vitro and in vivo on androgen-sensitive Pca cell lines in order to assess the differential biological properties of these two treatment modalities. Pulsed T treatment resulted in a greater inhibition than continuous T supplementation of tumor growth in vitro and in vivo. The effects of pulsed T treatment on tumor growth inhibition, G0/G1 cell cycle arrest, and tumor senescence was more pronounced than those obtained upon continuous T treatments. Mechanistic studies revealed that G0/G1 arrest and tumor senescence upon pulsed T treatment were associated with a marked decrease in cyclin D1, c-Myc and SKp2, CDK4 and p-Rb levels and upregulation of p27 and p-ERK1/2. Pulsed, but not continuous, T supplementation decreased the expression levels of AR, p-AR ser81 and CDK1 in both cellular models. The in vitro results were confirmed in an in vivo xenografts, providing evidence of a greater inhibitory activity of pulsed supraphysiological T supplementation than continuous treatment, both in terms of tumor volume and decreased AR, p-AR ser81 , PSA and CDK1 staining. The rapid cycling from hypogonadal to physiological or supra-physiological T intraprostatic concentrations results in cytostatic and senescence effects in preclinical models of androgen-sensitive Pca. Our preclinical evidence provides relevant new insights in the biology of Pca response to pulsed T supplementation