Outage Performance Analysis of Improper Gaussian Signaling for Two-User Downlink NOMA Systems with Imperfect Successive Interference Cancellation.

The improper Gaussian signaling (IGS) technique can improve the achievable rate of an interference-limited network by fully exploiting the second-order statistics of complex signaling. This paper addresses the outage performance analysis of a two-user downlink non-orthogonal multiple access (NOMA) system using the IGS technique in the presence of imperfect successive interference cancellation (SIC). The strong channel user (SU) adopts the IGS, while the weak channel user (WU) adopts the traditional proper Gaussian signaling (PGS). Considering a practical scenario where the transmitter has obtained the statistics of the channel coefficients instead of the instantaneous channel state information (CSI), the expressions of the achievable rates of both users under residual interference due to imperfect SIC are derived, together with their outage probabilities, subject to predetermined target rates and channel statistics. Given a fixed transmit power of the WU, both the transmit power and the degree of impropriety of the SU are optimized to minimize the outage probability subject to the outage constraint of the WU. Numerical results are provided to assess the benefits of the proposed IGS-based downlink NOMA system, which are consistent with the analysis.

[Treatment of femoral head replacement in elderly patients with femoral neck fracture complicated with uremia].

OBJECTIVE: To investigate the treatment method and effect of artificial femoral head replacement for elderly patients with femoral neck fracture complicated with uremia. METHODS: From January 2016 to December 2020, 21 elderly patients with femoral neck fracture complicated with uremia were treated with artificial femoral head replacement. There were 3 males and 18 females, aged 65 to 83 years old with an average of (77.2±1.9) years. All patients were complicated with uremia and required long-term maintenance of hemodialysis. The age of dialysis was 2 to 11 years with an average of (6.3±1.6) years, 2 to 3 times per week. The time from injury to admission to operation was 3 to 7 days with an average of (4.0±2.1) days. The anemia and hypoproteinemia of the patients were corrected preoperatively, and the serum potassium and creatinine indexes of the patients were adjusted by hemodialysis. RESULTS: All the incisions were healed in the first stage, and there were no complications of wound infection, prosthesis loosening, dislocation and deep vein thrombosis. All patients resumed routine hemodialysis in time to maintain the stability of serum creatinine and potassium levels. All 21 patients were followed up for 5 to 23 months with an average of (16.8±2.6) months. Harris scores changed from (24.8±2.5) scores preoperatively to (87.2±3.1) scores postoperatively. CONCLUSION: Elderly patients with femoral neck fracture combined with uremia underwent artificial femoral head replacement surgery, as long as the perioperative treatment is appropriate, with active postoperative rehabilitation treatment, can obtain a good clinical effect.

miR-376c-3p modulates the properties of breast cancer stem cells by targeting RAB2A.

MicroRNAs (miRNAs/miRs) negatively regulate gene expression and participate in various cellular processes. miRNA dysregulation is associated with cancer progression. The present study aimed to identify the miRNAs that participate in breast cancer tumorigenesis and determine the mechanism that underlies this. miRNA microarray data analysis and validation assays indicated that miR-376c-3p was downregulated in breast tumour tissues and breast cancer stem cells (BCSCs) compared with adjacent non-cancerous tissues and MCF-10A cells, respectively. Ras-related protein Rab-2A (RAB2A) was predicted as a target of miR-376c-3p, which was confirmed by conducting further experiments. miR-376c-3p regulated the BCSC population and the expression of stem cell regulatory genes by targeting RAB2A. By performing mammosphere, Cell Counting Kit-8, colony formation and transwell invasion assays, it was demonstrated that miR-376c-3p also inhibited BCSC self-renewal, proliferation and invasion by regulating RAB2A expression. Using a xenograft mouse model, it was revealed that miR-376c-3p overexpression suppressed breast cancer growth in vivo. In conclusion, the results indicated that miR-376c-3p targeted RAB2A to regulate BCSC fate and properties; therefore, miR-376c-3p may serve as a potential therapeutic target for breast cancer.

Step to improve neural cryptography against flipping attacks.

Synchronization of neural networks by mutual learning has been demonstrated to be possible for constructing key exchange protocol over public channel. However, the neural cryptography schemes presented so far are not the securest under regular flipping attack (RFA) and are completely insecure under majority flipping attack (MFA). We propose a scheme by splitting the mutual information and the training process to improve the security of neural cryptosystem against flipping attacks. Both analytical and simulation results show that the success probability of RFA on the proposed scheme can be decreased to the level of brute force attack (BFA) and the success probability of MFA still decays exponentially with the weights' level L. The synchronization time of the parties also remains polynomial with L. Moreover, we analyze the security under an advanced flipping attack.