Joint intra and inter-channel nonlinear compensation scheme based on improved learned digital back propagation for WDM systems.

In this paper, we improve the learned digital back propagation (LDBP) and propose a novel joint intra and inter-channel nonlinearity compensation scheme for polarization division multiplexing wavelength-division multiplexed (PDM-WDM) systems. From the perspective of interpretable neural network, the scheme realizes the alternating compensation of chromatic dispersion (CD) and nonlinearity based on physical models. The chromatic dispersion compensation (CDC) adopts one-dimensional convolution operation in the time domain. Moreover, the pulse-broadening effect is introduced into the overlap-and-save method. For nonlinear compensation, the improved joint model is applied, and the impact of the intra-channel pulse broadening and the walk-off effect between different channels caused by CD on the nonlinear effect is considered. To validate the effectiveness of the proposed scheme, we construct an 11-channel simulation system of 36 GBaud PDM uniform 16 quadrature amplitude modulation (PDM-16QAM) 1600 km and 64 GBaud PDM-64QAM 400 km, as well as a 5-channel experimental system of 28 GBaud PDM-16QAM 806.4 km. The simulation results show that the performance of PDM-16QAM with 0.5 steps per span and PDM-64QAM with 2 steps per span improve the Q-factor by approximately 0.75 dB and 0.54 dB at the optimal launch power, compared with the linear compensation scheme. The transmission performance of PDM-16QAM is higher than that of digital back propagation with 5 steps per span (DBP-5StPS), and the complexity is only 31.36% of that of DBP-5StPS. The performance of PDM-64QAM is higher than that of DBP-10StPS, with a complexity of 62.72%. The experimental results show that the performance of PDM-16QAM with 0.5 steps per span is improved with 0.86 dB Q-factor improvement compared with the linear compensation scheme at the optimal launch power, and the performance of the proposed scheme is higher than that of DBP-5StPS with a complexity of only 23.68%.

[Experimental study on improvement of cognitive impairment in Alzheimer's disease by different degrees of steaming and sunning of Polygoni Multiflori Radix based on fecal metabolomics].

The fecal metabolomics method was employed to investigate the cognitive improvement mechanism of Polygoni Multiflori Radix in Alzheimer's disease(AD) and examine the effects of different degrees of steaming and sunning on cognitive function in AD model mice. Additionally, the processing principle of Polygoni Multiflori Radix was discussed. Forty-eight 5-month-old APP/PS1 mice were randomly assigned to the following groups: model group, positive group, raw product group, three-steaming and three-sunning product group, six-steaming and six-sunning product group, and nine-steaming and nine-sunning product group. Seven negative control mice from the same litter were included as the blank group. After 150 days of intragastric administration, the learning and memory abilities of mice in each group were assessed by using the Barnes maze and dark avoidance tests. Fecal samples were collected for extensive targeted metabolomics testing. Principal component analysis(PCA), orthogonal partial least squares discriminant analysis(OPLS-DA), and other multivariate statistical methods were utilized to analyze metabolites in mouse feces. Comparison of behavioral results between the model group and different product groups demonstrated that the six-steaming and six-sunning product group exhibited significantly reduced latency in the Barnes maze positioning and navigation test(P<0.05), as well as a notable decrease in the number of errors in the space exploration experiment(P<0.05). Moreover, the latency of mice entering the dark box for the first time in the dark avoidance experiment was significantly prolonged(P<0.05), indicating the best overall improvement in the learning and memory ability of AD model mice. Metabolomics results revealed that compared with the model group, the differential metabolites in other groups in descending order were as follows: six-steaming and six-sunning product group > nine-steaming and nine-sunning product group > raw product group > three-steaming and three-sunning product group, encompassing 146, 120, 95, and 81 potential biomarkers, respectively. Among them, 16 differential metabolites were related to AD disease. Further comparisons based on the degree of processing indicated that the six-steaming and six-sunning product group exhibited the most significant adjustments in total metabolic pathways, particularly regulating the interconversion of pentose and glucuronic acid, as well as amino acid anabolism and other pathways. In summary, the mechanism of Polygoni Multiflori Radix after processing in enhancing the learning and memory ability of APP/PS1 mice may be associated with improved amino acid metabolism and increased energy metabolism in the body. The six-steaming and six-sunning yielded the best outcomes.

Effect of an Online Mindfulness-Based Stress Reduction Intervention on Postpandemic Era Nurses' Subjective Well-being, Job Burnout, and Psychological Adaptation.

This study explores the effects of an online mindfulness-based stress reduction intervention on postpandemic era nurses' subjective well-being, job burnout, and psychological adaptation. Previous studies on the psychological adaptability of nurses mainly focused on investigation rather than intervention. Ninety nurses were randomly classified into an intervention or control group. The intervention group received weekly online mindfulness-based stress reduction training for 8 weeks. The Subjective Well-being, Job Burnout, and Psychological Use scales were administered pre- and postintervention. Postintervention, nurses' positive emotions and life satisfaction significantly improved. Nurses' psychological adaptation was significantly higher postintervention than preintervention. The total scores for negative emotion, low personal accomplishment, and job burnout were significantly lower postintervention than preintervention. The scores for positive emotion and life satisfaction in the intervention group were significantly higher than those in the control group, and the scores for low personal accomplishment in the intervention group were significantly lower than those in the control group. Online mindfulness-based stress reduction interventions can improve nurses' subjective well-being, reduce job burnout, and improve their level of psychological adaptability. Moreover, it could promote nurses' ability to communicate mindfully with patients and their families. This intervention could help promote the development of mindfulness in the nursing field.

Joint nonlinear optical signal-to-noise ratio estimation and modulation format identification based on constellation-points trajectory information and multitask 1DCNN for WDM systems.

We propose a joint monitoring scheme of nonlinear optical signal-to-noise ratio (O S N R N L ) estimation and modulation format identification (MFI) in wavelength division multiplexing (WDM) systems. Based on the abundant information of both nonlinear noise (NLN) and modulation format (MF) in received signals, this scheme first counts the trajectory information of all adjacent constellation points, and then quantifies them into the adjacent matrix. Subsequently, the eigenvectors corresponding to the largest eigenvalues are extracted via eigen-decomposition of the adjacent matrix, which characterize the information of NLN and MF effectively. Finally, the eigenvectors are fed into multitask one-dimensional convolutional neural network to perform O S N R N L estimation and MFI simultaneously. To verify the effectiveness of the scheme, five-channel 28 GBaud polarization division multiplexing (PDM) -16/32/64 quadrature amplitude modulation (QAM) WDM simulation systems are built by VPI. The simulation results demonstrate that, for PDM-16/32/64QAM signals, the mean absolute errors of O S N R N L estimation are 0.18, 0.17, and 0.20 dB, respectively. At the same time, the identification accuracy rates of these three MFs have achieved 100% within the ranges of estimated O S N R N L . Furthermore, a three-channel 28 GBaud WDM experimental system is constructed to further investigate the effectiveness of trajectory information for O S N R N L estimation. The experimental results show that the O S N R N L estimation errors of PDM-16QAM are less than 0.5 dB. In addition, our analysis of complexity from two aspects of trajectory information extraction and neural network model shows that the overall complexity scale of this scheme is O(K i,3 M C i,3 C o,3).

Noise equalization scheme based on complex-valued ANN for multiple-eigenvalue modulated nonlinear frequency division multiplexing systems.

In multiple-eigenvalue modulated nonlinear frequency division multiplexing (NFDM) systems, the noise degrades the accuracy of the nonlinear Fourier transform (NFT) algorithm, resulting in perturbations in the received eigenvalues and the corresponding discrete spectrum. Moreover, with the increase in the number of eigenvalues and the order of the modulation formats, the impact of noise on the performance of the system is even more. A noise equalization scheme based on complex-valued artificial neural network (c-ANN) for multiple-eigenvalue modulated NFDM systems is proposed. This sceheme inputs the eigenvalues perturbation and the impaired discrete spectrum corresponding to the eigenvalues into the c-ANN in complex form. The scheme constructs a complex-valued logic structure with both amplitude and phase information, overlapping reuse input features and, thereby, effectively reducing the effect of noise on the multiple-eigenvalue NFDM system. The effectiveness of the scheme is verified in long-haul seven-eigenvalue modulated single-polarization NFDM simulation systems with 1 GBaud 16APSK/16QAM/64APSK/64QAM modulation formats, and the results show that the scheme outperforms the NFT receiving without equalization by 1 to 2 orders of magnitude in terms of bit error rate (BER). Among them, the transmission distance of the 64APSK signal after equalization exceeds 800 km while the BER meets 7% forward error correction (FEC) threshold, which is 600 km longer than that of the disequilibrium case, and the spectral efficiency (SE) can reach 1.85 bit/s/Hz. Compared with other schemes, the proposed scheme has better equalization performance under the same complexity, and the complexity can be reduced by half or even under the same performance.

AngioJet thrombectomy with extracorporeal membrane oxygenation support for an acute large-scale pulmonary embolism with bilateral atrial thrombosis: a case report of catastrophic antiphospholipid syndrome.

Background: Catastrophic Antiphospholipid Syndrome (CAPS), a severe systemic autoimmune disorder, predominantly causes life-threatening multi-organ failure, with a high mortality rate. It primarily affects small vessels, seldom impacting large vessels. Notably, acute massive pulmonary embolism (PE) with bilateral atrial thrombosis is an exceptional occurrence in CAPS. Acute pulmonary embolism (PE) is a common cardiovascular disease that progresses rapidly and has a high mortality rate. Acute massive PE combined with bilateral atrial thrombosis has an even higher mortality rate. PE treatments primarily include pharmaceuticals, catheter interventions, and surgical measures, with integrated treatment strategies demonstrating promising outcomes in clinical practice. Extracorporeal membrane oxygenation (ECMO) can provide cardiopulmonary support for the treatment of high-risk PE patients and is a proven therapeutic measure. Methods: This report presents the case of a 52-year-old male admitted due to fever and sudden onset of impaired consciousness, with cardiac ultrasound and pulmonary artery CT angiography revealing an acute large-scale pulmonary embolism accompanied by bilateral atrial thrombosis, with the condition rapidly worsening and manifesting severe respiratory and circulatory failure. With ECMO support, the patient underwent a thrombectomy using an AngioJet intervention. The diagnosis of CAPS was confirmed through clinical presentation and laboratory examination, and treatment was adjusted accordingly. Results: The patient made a successful recovery and was subsequently discharged from the hospital. Conclusion: In CAPS patients, the rare instance of acute massive PE accompanied by bilateral atrial thrombosis significantly risks severe respiratory and circulatory failure, adversely affecting prognosis. Early initiation of ECMO therapy is crucial, offering a vital opportunity to address the root cause. In this case report the patient was successfully treated with an AngioJet thrombectomy supported by ECMO.

Immobilization of Lipase in Cu-BTC MOF with Enhanced Catalytic Performance for Resolution of N-hydroxymethyl Vince Lactam.

Metal-organic frameworks (MOFs) can be used as the immobilization carriers to protect the physicochemical properties of enzymes and improve their catalytic performance. Herein, we report an in situ co-precipitation method to immobilize lipase from Candida sp. 99-125 in Cu-BTC MOF (BTC = 1, 3, 5-benzene tricarboxylic acid, H3BTC). Characterizations of the immobilized lipase (lipase@Cu-BTC) have confirmed the entrapment of lipase molecules in Cu-BTC MOF. The immobilized lipase has been successfully applied for resolving N-hydroxymethyl vince lactam (N-HMVL) and its catalytic activity is five times that of native enzyme. More importantly, we found that Cu-BTC MOF can afford powerful protection for enzyme in nearly dry organic solvent and endow the immobilized lipase with excellent reusability and storage stability. Our present study may widen the application of immobilized enzyme with MOF as the immobilized carrier.

Integrated Osteoinductive Factors─Exosome@MicroRNA-26a Hydrogel Enhances Bone Regeneration.

MicroRNAs (miRNAs) are a new therapeutic tool that can target multiple genes by inducing translation repression and target mRNA degradation. Although miRNAs have gained significant attention in oncology and in work on genetic disorders and autoimmune diseases, their application in tissue regeneration remains hindered by several challenges, such as miRNA degradation. Here, we reported Exosome@MicroRNA-26a (Exo@miR-26a), an osteoinductive factor that can be substituted for routinely used growth factors, which was constructed using bone marrow stem cell (BMSC)-derived exosomes and microRNA-26a (miR-26a). Exo@miR-26a-integrated hydrogels significantly promoted bone regeneration when implanted into defect sites; as the exosome stimulated angiogenesis, miR-26a promoted osteogenesis while the hydrogel enabled a site-directed release. Moreover, BMSC-derived exosomes further facilitated healthy bone regeneration by repressing osteoclast differentiation-related genes rather than damaging osteoclasts. Taken together, our findings demonstrate the promising potential of Exo@miR-26a for bone regeneration and provide a new strategy for the application of miRNA therapy in tissue engineering.

Prevalence of Feline Immunodeficiency Virus and Toxoplasma gondii in Feral Cats on St. Kitts, West Indies.

Toxoplasma gondii (T. gondii) is a cosmopolitan protozoan parasite that infects all warm-blooded species including humans. The definitive hosts of T. gondii are felid vertebrates including the domestic cat. Domestic cats shed oocysts for approximately two weeks in their feces after the primary infection. It has been shown that feline immunodeficiency virus (FIV) positive cats have a higher prevalence of and a higher titer of antibodies to T. gondii than those of FIV-negative cats. The main purposes of this study were to determine FIV prevalence and to investigate the oocysts shedding in FIV-positive and FIV-negative feral cats on St. Kitts. Fecal samples were collected from feral cats while their FIV statues were determined using a commercial SNAP kit. Total fecal DNA of each cat was tested for the presence of T. gondii DNA using a polymerase chain reaction (PCR) consistently detecting one genome equivalent. A FIV-positive status was detected in 18 of 105 (17.1%, 95% confidence interval (CI): 9.9%-24.3%) feral cats sampled. Furthermore, males were three times more likely to be FIV positive than females (p = 0.017) with an odds ratio of 3.93 (95% CI: 1.20-12.89). Adults were found to have at least twice the prevalence of FIV compared to cats younger than one year of age (p = 0.056) with an odds ratio of 3.07 (95% CI: 0.94-10.00). Toxoplasma gondii DNA was not detected in the feces of any of the 18 FIV-positive (95% CI: 0%-0.18%) and 87 FIV-negative cats (95% CI: 0%-0.04%). A follow-up study with a much bigger sample size is needed to prove or disprove the hypothesis that FIV-positive cats have a higher prevalence of shedding T. gondii oocysts than FIV-negative cats.

Small Indian Mongooses (Herpestes auropunctatus) Serve As Reservoirs of Bartonella henselae and Rickettsia felis Vectored by Ctenocephalides felis.

Small Indian mongooses (SIMs, Herpestes auropunctatus) have invasively inhabited over 60 islands worldwide. They have been confirmed as a reservoir of rabies, leptospirosis, and salmonellosis; however, their role in the epidemiology of other zoonoses is little known. On St. Kitts, as well as other islands, SIMs harbor Ctenocephalides felis, which can vector several zoonotic diseases. In this study, SIMs were examined for fleas, and the collected fleas analyzed by PCR and DNA sequencing for Bartonella henselae, Rickettsia felis, Yersinia pestis, and Dipylidium caninum. Of the 87 SIMs, 75 (86.2%) harbored C. felis. C. felis recovered from nine (10.3%), one (1.1%), and one (1.1%) of the SIMs was positive for B. henselae, R. felis, and D. caninum, respectively. These data indicate that SIMs serve as an additional reservoir of B. henselae and R. felis, which should be taken into consideration in control and prevention of these rapidly emerging zoonoses.