Machine-learning-based optical spectrum feature analysis for DoS attack detection in IP over optical networks.

In this paper, we introduce a novel approach for detecting Denial of Service (DoS) attacks in software-defined IP over optical networks, leveraging machine learning to analyze optical spectrum features. This method employs machine learning to automatically process optical spectrum data, which is indicative of network security status, thereby identifying potential DoS attacks. To validate its effectiveness, we conducted both numerical simulations and experimental trials to collect relevant optical spectrum datasets. We then assessed the performance of three machine learning algorithms XGBoost, LightGBM, and the BP neural network in detecting DoS attacks. Our findings show that all three algorithms demonstrate a detection accuracy exceeding 97%, with the BP neural network achieving the highest accuracy rates of 99.55% and 99.74% in simulations and experiments, respectively. This research not only offers a new avenue for DoS attack detection but also enhances early detection capabilities in the underlying optical network through optical spectrum data analysis.

Reconfigurable all-optical pattern recognition for PSK and QAM signals in high-speed optoelectronic firewalls.

In the fifth generation fixed networks (F5G) era, full-fiber-connected optical networks support emerging bandwidth-hungry services. However, optical networks are vulnerable to attack by tapping or other methods, which has been paid more and more attention in modern optical infrastructure. Therefore, high-speed optoelectronic firewalls appear as one of the promising technologies to guarantee security. The most significant and challenging component of a high-speed optoelectronic firewall is all-optical pattern recognition, especially for more advanced high-order modulation formats such as phase shift keying (PSK) or quadrature amplitude modulation (QAM) to satisfy efficient enhanced fixed broadband in F5G. In this paper, what we believe to be a novel reconfigurable all-optical pattern recognition system for PSK and QAM signals is proposed with two implementation architectures. The proposed system mainly consists of a generalized XNOR (GXNOR) and a recirculating loop. The two implementation architectures are precisely two realization methods of the GXNOR part. One employs two cascaded IQ Mach-Zehnder modulators and the other is implemented by the four-wave mixing. The numerical simulation results demonstrate that the two implementation architectures can both achieve all-optical pattern recognition for the reconfigurable high-order modulation formats of QPSK, 8PSK, and 16QAM with the recorded baud rate of 260GBaud.

Joint Encryption Model Based on a Randomized Autoencoder Neural Network and Coupled Chaos Mapping.

Following an in-depth analysis of one-dimensional chaos, a randomized selective autoencoder neural network (AENN), and coupled chaotic mapping are proposed to address the short period and low complexity of one-dimensional chaos. An improved method is proposed for synchronizing keys during the transmission of one-time pad encryption, which can greatly reduce the usage of channel resources. Then, a joint encryption model based on randomized AENN and a new chaotic coupling mapping is proposed. The performance analysis concludes that the encryption model possesses a huge key space and high sensitivity, and achieves the effect of one-time pad encryption. Experimental results show that this model is a high-security joint encryption model that saves secure channel resources and has the ability to resist common attacks, such as exhaustive attacks, selective plaintext attacks, and statistical attacks.

Reconfigurable all-optical format conversion for 16QAM/8QAM by employing PSA in HNLF.

Extensive investigations are undertaken on the feasibility of utilizing phase sensitive amplification (PSA) in highly nonlinear fiber (HNLF) to achieve a reconfigurable 16QAM/8QAM all-optical format conversion for optical data center networks. A comprehensive theoretical model is developed and subsequently verified, based on numerical simulations undertaken to explore the effectiveness of the nonlinear effects of phase insensitive amplification, PSA, and self phase modulation for the proposed all-optical format conversion scheme. It is demonstrated that the proposed scheme can achieve a reconfigurable all-optical format conversion from a 16QAM signal to two quadrature phase shift keying (QPSK) signals or from an 8QAM signal to one QPSK signal and one binary phase shift keying signal with data rates of 92Gbps and 69Gbps for 16QAM and 8QAM signals, respectively.

All-optical encryption/decryption of DmPSK signals with key steganography for photonic layer security.

In the 5th Generation Fixed networks (F5G) era, full-fiber-connected optical networks support emerging bandwidth-hungry services. However, optical networks are vulnerable to attack by tapping or other methods, which has been paid more and more attention in modern optical infrastructure. Therefore, optical Exclusive OR (XOR) encryption/decryption for advanced modulation formats used for F5G appears as one of the promising technologies to guarantee security. Some current solutions either leave potential security hazards because of the degenerate four-wave mixing and keys without special treatment or are cost-consuming due to employing multiple wavelengths and coherent receivers. In this paper, a novel all-optical encryption/decryption system for Differential m-Phase Shift Keying (DmPSK) signals occupying only a single wavelength with key steganography is proposed and simulated. The proposed system mainly consists of a generalized XOR (GXOR) part and a steganography part. We implement the GXOR part by the cascaded IQ Mach-Zehnder Modulators and the steganography part by the Equvilent-Phase-Shifted Super-Structured Fiber Bragg Grating (EPS-SSFBG). The numerical simulation results demonstrate that the GXOR implementation can achieve reconfigurable encryption/decryption of DQPSK (m = 4) or D8PSK (m = 8) signals merely with a single wavelength and a differential direct-detection receiver. And the EPS-SSFBG can enhance key security in a cost-efficient method as well. The system can work at the recorded bit rate of 260Gbps, which can be applied to enhance the photonic layer security in F5G and beyond.

Effect of hexavalent chromium-induced ribosomal DNA copy number variation on DNA damage response in various cell lines / 预防医学

Objective@#To investigate the effect of ribosomal DNA (rDNA) copy number variation caused by hexavalent chromium exposure on DNA damage response in different cell lines, so as to provide insights into the involvement of hexavalent chromium-induced rDNA copy number variation in DNA damage responses. @*@#Methods Human lung epithelial BEAS-2B cells and human embryonic lung MRC-5 cells were treated with 2 μmol/L potassium dichromate for 24 hours, and then cells were transferred to fresh media for further incubation, while cells treated with the same volume of phosphate buffer solution served as controls. Cells treated with potassium dichromate for 24 hours, and 3 and 7 days post-detoxification, were harvested, and rDNA copy number was quantified in cells using a quantitative fluorescent real-time PCR assay. Cell cycle, apoptosis and DNA damage were detected using a Muse cell analyzer, and the DNA damage was evaluated with the proportion of ataxia telangiectasia-mutated (ATM) gene activation, proportion of double-strand DNA breaks and the percentage of the H2A.X variant histone phosphorylatio.@*@# Results The 45S and 5S rDNA copy numbers of were significantly higher in MRC-5 cells than in BEAS-2B cells [(1.54±0.26) vs. (1.02±0.18), P<0.05; (6.97±1.07) vs. (3.00±0.15), P<0.05]. The 45S rDNA copy number was lower in MRC-5 cells 3 days post-detoxification (0.80±0.04) than in controls (P<0.05), and was higher in BEAS-2B cells 3 days post-detoxification (1.43±0.07) than in controls (P<0.05) . G0/G1 phase arrest was found in MRC-5 cells 24 hours post-treatment, and the apoptotic rates were significantly higher in MRC-5 cells 3 and 7 days post-detoxification than in controls [(11.53±1.53)%, (18.33±0.70)% vs. (3.53±0.93)%, P<0.05]. The overall apoptotic rates 24 hours post-treatment and 3 days post-detoxification [(2.80±0.17)%, (3.33±0.57)% vs. (1.53±0.61)%, P<0.05], proportion of ATM gene activation 3 days post-detoxification [(3.37±0.67%) vs. (1.18±0.22)%, P<0.05], proportion of double-strand DNA breaks 3 days post-detoxification [(4.45±0.85)% vs. (0.97±0.21)%, P<0.05] and percentage of the H2A.X variant histone phosphorylation 3 days post-detoxification [(1.68±0.56)% vs. (0.29±0.06)%, P<0.05] in BEAS-2B cells were higher than in controls. @*Conclusions@#Hexavalent chromium-induced rDNA copy number variation affects DNA damage response in different cell lines. A stronger DNA damage response is found in BEAS-2B cells with a low rDNA copy number, and a relative stable response is observed in MRC-5 cells with a high rDNA copy number.

Application Value of Management Model Based on "Zero Tolerance" Concept in Pressure Ulcer Management.

Background: Pressure injuries are the most prevalent health problem worldwide. Improving the quality of hospital pressure injury management is an important indicator to improve the quality of hospital management. Objective: To explore the application value of the management model centered on the concept of "zero tolerance" in the management of pressure ulcers (PU). Methods: The effects of conventional management mode and management mode centered on the concept of "zero tolerance" on PU patients and nursing staff were retrospectively analyzed. The patients were evaluated by the general comfort questionnaire (GCQ), Generic Quality of Life Inventory 74 (GQOL-74), and pressure ulcer healing scale (PUSH). At the same time, the satisfaction of PU patients and nursing staff with different management modes was investigated. Results: When comparing the conditions of patients under different management modes, it was found that the "zero tolerance" management mode can improve the comfort and quality of life of patients during hospitalization. Compared with the conventional management mode, the "zero tolerance" management mode can significantly improve the degree of pressure ulcer healing in patients. In addition, the "zero tolerance" management model can not only improve the satisfaction of patients with management but also improve the satisfaction of nursing staff with management. Conclusion: Standardized management of PU patients with the concept of "zero tolerance" as the core can improve the health status and quality of life of patients, promote wound healing, and improve the satisfaction of patients and nurses with the management plan.

Association of SGK1 Polymorphisms With Susceptibility to Coronary Heart Disease in Chinese Han Patients With Comorbid Depression.

There is a strong link between heart disease and depression, both of which are closely related to lifetime stress exposure. Serum/glucocorticoid-regulated kinase 1 (SGK1) is a stress-responsive gene with a pivotal role in both the heart and brain. To determine the role of SGK1 polymorphisms (rs2758151, rs1743963, rs9493857, rs1763509, rs9376026, and rs9389154) in susceptibility to comorbid coronary heart disease (CHD) and depression, we conducted a hospital-based case-control study involving 257 CHD cases (including 69 cases with depression and 188 cases without depression) and 107 controls in a Chinese Han population. Six single-nucleotide polymorphisms (SNPs) in the SGK1 gene were successfully genotyped by polymerase chain reaction-ligase detection reaction (PCR-LDR) assay. Our results showed no significant differences in SGK1 genetic polymorphisms between CHD patients and controls, whereas significant associations were observed between SGK1 SNPs (rs1743963 and rs1763509) and the development of depression in CHD patients (P = 0.018 by genotype, P = 0.032 by allele; P = 0.017 by genotype, P = 0.003 by allele, respectively). However, none of these associations remained significant after Bonferroni correction (P = 0.054 for rs1743963; P = 0.051 for rs1763509). Interestingly, both the GG genotype of SGK1 rs1743963 and AA genotype of SGK1 rs1763509 were associated with a higher risk of depression in CHD patients; for rs1763509, the Patient Health Questionnaire-9 (PHQ-9) scores in the carriers of the risk genotype for comorbid depression, AA, were significantly higher than in GG and AG carriers (P = 0.008). Notably, haplotype analysis indicated that haplotype GGA significantly increased the risk of depression in CHD patients (P = 0.011, odds ratio (OR) = 1.717, 95% confidence interval (CI) = 1.132-2.605), whereas haplotype AAG may be a protective factor for CHD patients with comorbid depression (P = 0.038, OR = 0.546, 95% CI = 0.307-0.972). It should be noted that only the significance of haplotype GGA survived after Bonferroni adjustment (P = 0.044) and that no significant differences were found for other SGK1 SNPs (rs2758151, rs9493857, rs9376026, and rs9389154) between CHD patients with and without depression. These findings, for the first time, elucidate the important role of SGK1 variants in the comorbidity of CHD and depression.

Simulating and Testing Microvibrations on an Optical Satellite Using Acceleration Sensor-Based Jitter Measurements.

The present study uses a method to address microvibrations effects on an optical satellite by combining simulations and experiments based on high-precision acceleration sensors. The displacement and angular displacement of each optical component can be obtained by introducing flywheel perturbation data from a six-component test bench to the finite element model of the optical satellite. Combined with an optical amplification factor inferred from the linear optical model, the pixel offset of the whole optical system is calculated. A high accuracy and broad frequency range for a new microvibration measurement experimental system is established to validate the simulation. The pixel offset of the whole optical system can be measured by testing the acceleration signals of each optical component and calculating optical amplification factors. The results are consistent with optical imaging test results, indicating correctness of the experimental scheme and the effectiveness of the simulation. The results suggest that the effect of microvibrations on a camera can be verified by using mechanical simulators instead of a whole optical camera for the experiment scheme, which is demonstrated to be an effective way for increasing efficiency in jitter measurements.

The Involvement of Renin-Angiotensin System in Lipopolysaccharide-Induced Behavioral Changes, Neuroinflammation, and Disturbed Insulin Signaling.

Brain insulin signaling is accounted for the development of a variety of neuropsychiatric disorders, such as anxiety and depression, whereas both inflammation and the activated renin-angiotensin system (RAS) are two major contributors to insulin resistance. Intriguingly, inflammation and RAS can activate each other, forming a positive feedback loop that would result in exacerbated unwanted tissue damage. To further examine the interrelationship among insulin signaling, neuroinflammation and RAS in the brain, the effect of repeated lipopolysaccharide (LPS) exposure and co-treatment with the angiotensin II (Ang II) receptor type 1 (AT1) blocker, candesartan (Cand), on anxiety and depression-like behaviors, RAS, neuroinflammation and insulin signaling was explored. Our results demonstrated that prolonged LPS challenge successfully induced the rats into anxiety and depression-like state, accompanied with significant neural apoptosis and neuroinflammation. LPS also activated RAS as evidenced by the enhanced angiotensin converting enzyme (ACE) expression, Ang II generation and AT1 expression. However, blocking the activated RAS with Cand co-treatment conferred neurobehavioral protective properties. The AT1 blocker markedly ameliorated the microglial activation, the enhanced gene expression of the proinflammatory cytokines and the overactivated NF-κB signaling. In addition, Cand also mitigated the LPS-induced disturbance of insulin signaling with the normalized phosphorylation of serine 307 and tyrosine 896 of insulin receptor substrate-1 (IRS-1). Collectively, the present study, for the first time, provided the direct evidence indicating that the inflammatory condition may interact with RAS to impede brain insulin pathway, resulting in neurobehavioral damage, and inhibiting RAS seems to be a promising strategy to block the cross-talk and cut off the vicious cycle between RAS and immune system.

Alleviating Effect of Antidepressant Treatment on Psychiatric Symptoms and Cardiac Conditions in a Patient with Coronary Slow Flow Comorbid with Depression and Anxiety.

BACKGROUND Depressive patients are considerably more likely to suffer cardiovascular disease (CVD), and in patients with CVD, depression is a predictor of poor outcome. Recent findings suggest higher rates of depression and anxiety in patients with coronary slow flow (CSF). However, there is no research investigating whether the antidepressant treatment can mitigate psychiatric symptoms and cardiac conditions in CSF patients comorbid with depression. CASE REPORT The patient was a 52-year-old Chinese female with frequent chest pain. The patient had serious TIMI (thrombolysis in myocardial infarction) grade 2 flow without any coronary stenosis, but comorbid with depression and anxiety. The CSF was very likely associated with her mental health condition, given that the chest distress and intermittent chest pain followed psychological stress and disturbed sleep. Therefore, paroxetine was used under the circumstances of the poor effect of cardiovascular active drugs. We found that the adjunctive use of paroxetine not only improved the psychiatric symptoms, but also alleviated the cardiac conditions. CONCLUSIONS Our findings strengthen the importance of the treatment of psychiatric symptoms in patients with CSF and this finding should promote randomized controlled trials in a larger population to confirm the beneficial effects of antidepressant treatment on psychiatric symptoms and cardiac conditions in CSF patients with psycho-cardiac conditions.

Tamoxifen Prevents D-galactosamine/Lipopolysaccharide-Induced Murine Acute Hepatic Failure through Inhibition of Oxidative Stress and Mmd-2 Upregulation.

Oxidative stress is considered one of the major mechanisms underlying lipopolysaccharide (LPS)-induced acute liver failure (ALF). Tamoxifen has been reported to ameliorate LPS-induced ALF via the induction of monocyte to macrophage differentiation-associated 2 (Mmd-2). Whether antioxidant effects are involved remains unknown. Mice were given tamoxifen (TAM) once a day for 3 days. Twelve hours later, d-galactosamine (GaIN) and LPS were injected intraperitoneally to induce ALF. N-Acetylcysteine (NAC) was administered immediately after ALF induction as a positive control. The results showed that serum transaminases increased and hepatic antioxidants decreased significantly in the model group. ALF was alleviated markedly by TAM or NAC treatment. This demonstrated that ALF may be associated with excessive oxidative stress caused by decreased expression of antioxidant enzymes. Both TAM and NAC increased the levels and activity of these antioxidant enzymes significantly (p < 0.05). Hepatic Mmd-2 expression was downregulated in the control group while remaining stable or exhibiting elevated levels in the TAM or NAC groups. The results indicate that TAM may protect mice from GaIN/LPS-induced ALF through increased activity of antioxidant enzymes and upregulation of Mmd-2 expression.

Fish oil supplementation attenuates neuroinflammation and alleviates depressive-like behavior in rats submitted to repeated lipopolysaccharide.

PURPOSE: Depression is frequently associated with inflammation, whereas omega-3 polyunsaturated fatty acids (PUFAs) primarily found in fish oil possess anti-inflammatory properties. Although converging studies suggest an antidepressant effect of PUFAs, there is limited evidence directly linking the neuro-immune modulating features of PUFAs to the antidepressant actions. METHODS: Therefore, we assessed the effects of fish oil (FO) supplementation on behavioral changes, inflammatory cytokine expression and oxidative reactions in frontal cortex and hippocampus of rats following repeated peripheral immune challenge by lipopolysaccharide (LPS) for 2 weeks (500 µg/kg every other day). RESULTS: Repeated LPS administration induced the rats to a depressive-like state and increased mRNA expression of pro-inflammatory cytokines, including 1L-1ß, 1L-6 and TNF-α, in frontal cortex and hippocampus. FO supplementation attenuated the LPS-induced abnormal behavior and brain inflammatory response. Concurrent with the antidepressant action, FO also reduced LPS-induced oxidative reactions and neural apoptosis in the rat brain, as evidenced by decreased malondialdehyde (MDA) production, increased catalase activities and inhibited pro-apoptotic protein Bax mRNA expression. In addition, FO inhibited activation of NF-κB and iNOS induced by LPS. Interestingly, we found FO suppressed the activation of the inflammasome NLRP3 and ionotropic purinergic receptor P2X7R evoked by LPS, suggesting a potential anti-inflammatory mechanism for PUFAs. Besides, FO also restored the LPS-induced neurochemical disturbance, especially the balance between serotonin and kynurenine branches of tryptophan metabolism, which is tightly associated with depression. CONCLUSIONS: These findings provide novel insights into the antidepressant action of PUFAs and further strengthen the link between inflammation and depression.

Design and optimization for main support structure of a large-area off-axis three-mirror space camera.

To ensure excellent dynamic and static performance of large-area, off-axis three-mirror anastigmat (TMA)-space cameras, and to realize a lighter weight for the entire system, a truss support structure design is applied in this study. In contrast to traditional methods, this paper adopts topology optimization based on the solid isotropic materials with penalization method on the truss structure design. Through reasonable object function and constraint choice, optimal topology results that have concerned the effect of gravity in the X, Y, and Z axis are achieved. Subsequently, the initial truss structure is designed based on the results and manufacturing technology. Moreover, to reduce the random vibration response of the secondary mirror and fold mirror without mechanical performance decline of the whole truss, a weighted optimization of truss size is proposed and the final truss structure is achieved. Finite element analysis and experiments have confirmed the reliability of the design and optimization method. The designed truss-structure camera maintains excellent static performance with the relative optical axis angle between the primary mirror and corresponding mirrors (secondary mirror and fold mirror) being less than 5.3 in. Dynamic performances, such as random and sinusoidal vibration responses, also met the requirements that the acceleration RMS value for mount points of the fold mirror should be less than 20 g and the primary frequency reached 97.2 Hz.