Taking the broadband chaotic output from a weak-resonant-cavity Fabry-Perot laser diode (WRC-FPLD) under filtered feedback as a chaotic entropy source, we propose and experimentally demonstrate a scheme for generating fast physical random bits (PRBs) at a rate up to 240 Gbits/s. First, we investigate the dependence of the dynamical properties of the filtered feedback WRC-FPLD on the system parameters, and determine the optimized parameter region for generating wavelength-tunable and broadband chaotic signals. Second, a broadband chaotic signal with a bandwidth beyond 20 GHz output from the WRC-FPLD is sampled and transferred to a digital bit sequence by an 8-bit analog-to-digital converter at a rate of 40 GS/s. Finally, by utilizing multi-bit post-processing method, PRBs is generated at a rate up to 240 Gbits/s, which can pass all the 15 NIST statistics tests and meet the strict criteria of the statistical bias and the serial correlation coefficient.

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Taking the chaotic output from a master-slave framework chaotic system as chaotic entropy resource, we propose a scheme for acquiring dual-channel high-speed physical random bits (PRBs). For such a scheme, a vertical-cavity surface-emitting laser (VCSEL) under polarization-preserved optical feedback from a fiber Bragg grating is utilized as the master VCSEL (M-VCSEL). Under suitable operating parameters, both X and Y polarization components (X-PC and Y-PC) of the M-VCSEL can output chaotic signals with comparable power and weak time-delay signatures. The chaotic outputs from the X-PC and Y-PC of the M-VCSEL are divided into two parts, and then injected into the corresponding polarized component of another VCSEL (named as slave VCSEL, S-VCSEL) after undergoing different flight-time, and such an injection method is named as dual-path polarization-preserved optical injection (DP-PPOI). The X-PC and Y-PC in the S-VCSEL under DP-PPOI can simultaneously output chaotic signals with enhanced bandwidth, which are quantified by 8-bit analog-to-digital converters and taken as the entropy sources for generating dual-channel bit sequence after adopting m least significant bits (m-LSBs) extraction and logical exclusive-OR post-processing. Finally, the randomness of the bit sequences generated under optimized parameters is tested by NIST SP 800-22 statistical test suite. The results demonstrate that dual-channel random bits at rate of 500 Gbit s −1 can be obtained, and the rate of random bits can be further increased to 1 Tbit s −1 through adopting cross-merging method.

Background Prostate artery embolization (PAE) is a relatively safe and effective alternative method for the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia. The adverse events caused by PAE are primarily mild, including urinary tract infection, acute urinary retention, dysuria, fever, etc. Severe complications, such as nontarget organ embolism syndrome or penile glans ischemic necrosis, are rare. Here, we report a case of severe ischemic necrosis of the glans penis after PAE and review the literature. Case presentation An 86-year-old male patient was admitted to the hospital due to progressive dysuria with gross hematuria. The patient underwent placement of a three-way urinary catheter to facilitate continuous bladder flushing, hemostasis, and rehydration. After admission, his hemoglobin decreased to 89 g/L. After an examination, the diagnosis was benign prostatic hyperplasia with bleeding. During communication with the patient regarding treatment, he requested prostate artery embolization due to his advanced age and concomitant disease status. He underwent bilateral prostate artery embolization under local anesthesia. His urine gradually turned clear. However, on the 6th day after embolization, the glans gradually showed ischemic changes. On the 10th day, there was partial necrosis and blackening of the glans. The glans completely healed, and the patient was able to urinate smoothly on the 60th day after local cleaning and debridement, the administration of pain relief, anti-inflammatory and anti-infection agents, and external application of burn ointment. Conclusion Penile glans ischemic necrosis after PAE is rare. The symptoms include pain, congestion, swelling, and cyanosis in the glans.

Background Although elevated homocysteine levels have been shown to affect penile erection, the relationship between homocysteine and erection at the tip or base of the penis has not been extensively studied. Results We found that homocysteine levels were negatively correlated with the average event rigidity of the base (r = -0.2225, p = 0.0142). Homocysteine levels were also negatively correlated with the average maximum rigidity of the base (r = -0.2164, p = 0.0171). In particular, homocysteine levels were negatively correlated with ∆ Tumescence of the tip (r = -0.1866, p = 0.0404). Similarly, homocysteine was negatively correlated with ∆ Tumescence of the base (r = -0.2257, p = 0.0128). Conclusion Our data showed that homocysteine inhibits penile erection. At the same time, homocysteine levels were negatively correlated with the parameters of the AVSS-RigiScan test.