Generalized Rayleigh quotient optimization method for inter-channel nonlinearity compensation in coherent optical communication systems.

Inter-channel nonlinearity compensation plays a crucial role in wavelength division multiplexing (WDM) systems for improving transmission capacity and distance. In this work, we propose a novel, to the best of our knowledge, inter-channel nonlinearity compensation method called generalized Rayleigh quotient optimization (GRQO) method with two different working modes. In an 8 × 64 GBaud 16-ary quadrature amplitude modulation (16-QAM) experimental system over 1600 km standard single-mode fiber (SSMF), the proposed method shows a 0.40 dB Q2 factor improvement over nonlinear polarization cross talk canceller (NPCC) with a moderately low computational complexity of about 2000 real multiplications per bit (RMb).

Meta-analysis of Clinical Efficacy of Aspirin and Low Molecular Weight Heparin in the Treatment of Recurrent Spontaneous Abortion.

Objective: To investigate the clinical effect of aspirin (ASA) combined with low molecular weight heparin (LMWH) in the treatment of recurrent spontaneous abortion (RSA). Methods: PubMed, Cochrane, Wanfang, CNKI, and other databases were searched to collect randomized controlled trials (RCT) of aspirin combined with LMWH in the treatment of RSA from the establishment of the database to July 31, 2023. The literature was screened, and the information was extracted according to the pre-established criteria. The Reviews Manager 5.4 software was used for data analysis. Results: A total of 10 RCTs containing 1865 patients with RSA were included in this study. Meta-analysis showed that the regimen of aspirin combined with LMWH treatment significantly increased the neonatal birth rate (P < .01); and the occurrence of preeclampsia was significantly reduced when compared with regimens such as aspirin alone (P = .02); there were no significant differences between the two groups in the incidence of preterm birth (P = .21), neonatal birth weight (P = .38), the incidence of a small amount of patient hemorrhage (P = .41) and fetal growth restriction (P = .93). Conclusion: The combination of aspirin and LMWH offers a clinically significant improvement in live birth rates and reduction in preeclampsia for RSA patients, suggesting a beneficial strategy for clinical practice and future research directions.

The identification and functional analysis of CircRNAs in endometrial receptivity of mice with polycystic ovary.

The disorders of endometrial receptivity and ovulatory dysfunction are both significant causes of infertility in patients with polycystic ovary syndrome (PCOS). In this study, we investigated the expression profile and functional implications of circular RNAs (circRNAs) in the endometrial receptivity of PCOS-affected mice. Twenty-four female C57BL/6 mice were divided into PCOS and normal control groups. The PCOS group received subcutaneous DHEA treatment, while the control group remained untreated. Gene chip technology was utilized to analyze circRNA expression in endometrial tissues on the fourth day of gestation with subsequent bioinformatics analyses into circRNA functions. Furthermore, endometrial epithelial cells were used to determine represented circRNA functions. Results showed that the PCOS group exhibited 205 differentially expressed circRNAs, with 147 upregulated and 58 downregulated ones. qRT-PCR confirmed differential expression of circRNAs, including circRNA_38548, circRNA_001686, circRNA_38550, and circRNA_27938. Predicted target genes and a circRNA-miRNA-mRNA regulatory network were constructed. Additionally, four circRNAs (circRNA_38548, circRNA_38550, and circRNA_001686) were identified to contribute to abnormal endometrial receptivity by regulating genes such as Lifr, FOXK1, FOXO1, HOXA10, through interactions with miRNAs. Further research is warranted to elucidate the underlying mechanisms involving these circRNAs.

Joint timing recovery and adaptive equalization based on training sequences for PM-16QAM faster-than-Nyquist WDM systems.

Since the timing error detectors sensitivity (TEDS) of the timing recovery algorithm is close to zero under the singularity condition of azimuth θ about ±π/4 and differential group delay (DGD) about n × 1/2T (n is an odd number, T is the symbol period), it makes the squared Gardner phase detector (SGPD) timing recovery algorithm fail to achieve timing synchronization. What's worse, in the faster-than-Nyquist wavelength division multiplexing (FTN-WDM) systems, the tight filtering introduces inter-symbol-interference (ISI) so severe that the convergence cost of the SGPD timing recovery algorithm is extremely large even under the non-singularity condition. This paper proposes a joint timing recovery and adaptive equalization scheme for FTN coherent systems based on training sequences that could calculate channel matrix and indicate polarization characteristics, thereby avoiding the influence of azimuth on adaptive equalization and polarization demultiplexing (AEPD) embedded in the timing recovery feedback loop. Since embedded AEPD could compensate for most of DGD, the TEDS could be restored and timing synchronization could be achieved under the above adverse conditions. Thanks to the innovative scheme, which equalizes ISI and DGD during the feedback process of the loop, the convergence cost of timing recovery could be reduced with similar computational complexity compared with the conventional one. The simulation results of 128 GBaud polarization multiplexing (PM) 16-quadrature amplitude modulation (QAM) FTN-WDM transmission systems demonstrate that the proposed scheme could stably achieve timing synchronization under the singularity condition. And compared with the conventional scheme, the convergence cost is reduced by at least 42% @ 0.9 acceleration factor. In addition, 40 GBaud PM-16QAM FTN experiment results show that the proposed scheme could not only achieve timing synchronization stably but also exhibit an optical signal-to-noise ratio tolerance gain of 0.8 dB compared with the conventional scheme under 800 km transmission.

Analysis of the guidance and predictive value of uterine artery flow parameters in patients with recurrent spontaneous abortion.

OBJECTIVE: To analyze the uterine artery blood flow parameters of patients with recurrent spontaneous abortion (RSA) at different gestational ages and to investigate the effects of aspirin and low molecular weight heparin (LMWH) on uterine artery blood flow parameters and pregnancy outcomes. METHODS: This was a retrospective cohort study involving analysis of clinical data for 140 patients: 47 in an aspirin group, 49 in a combination group, and 44 in a control group. The uterine artery blood flow parameters of the three groups in the middle luteal period and 10th, 12th, 16th, and 20th gestational weeks were compared. Trends in uterine artery flow parameters were predicted by function fitting, and the uterine artery flow parameters and pregnancy outcomes between different drug administration regimens were compared. RESULTS: With increasing gestational age, the uterine artery blood flow parameters of the three groups gradually decreased. In the middle luteal phase, the uterine artery blood flow parameters (mRI, mPI, mS/D) of the recurrent spontaneous abortion group, that is, the aspirin and combination groups, were significantly higher than those of the control group. Uterine artery blood flow parameters from 10 to 20 weeks of gestation were as follows: combined group < aspirin group < normal pregnancy group. The mean resistance index (mRI) in the combination group decreased most rapidly compared with the aspirin group between 10 and 20 weeks of gestation. The live birth rate was higher in the combination group than in the aspirin group. CONCLUSIONS: Both aspirin and aspirin combined with LMWH can reduce uterine artery blood flow parameters, and combination therapy is superior to aspirin alone. In the RSA group, the rate of mRI decline may predict pregnancy outcome to some extent. Combination therapy can improve the live birth rate and reduce the miscarriage rate.

Effects and safety of GnRH-a as a luteal support in women undertaking assisted reproductive technology procedures: follow-up results for pregnancy, delivery, and neonates.

PURPOSE: To investigate the effects and safety of gonadotropin releasing hormone analogue (GnRH-a) as an addition to progesterone luteal support in women who underwent in vitro fertilization/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET) and achieved a clinical pregnancy. METHODS: A retrospective analysis was conducted on 214 patients who underwent IVF/ICSI-ET procedures with standard long mid-luteal protocol, of which 123 received GnRH-a-free protocol and 91 received GnRH-a-added protocol. The patients' pregnancy and delivery course, and their neonates' status at birth and growth/development after birth were statistically compared. RESULTS: There was no significant difference between both study groups regarding embryo risks and maternal complications during early pregnancy. as well as fetal risks during the middle and late stages and neonate risks during birth, except that the twin pregnancies of the GnRH-a-added group had a considerably greater male/female ratio, and a significantly higher rate of premature delivery and low birth weight than those of the GnRH-a-free group. In addition, there was no significant difference in neonate risks within 2 years after birth between both cohorts. CONCLUSION: With precautions taken to control the number of implanted embryos and reduce the incidence of twinning pregnancy, the addition of GnRH-a to luteal support is relatively safe and effective.

Edaravone attenuates hippocampal damage in an infant mouse model of pneumococcal meningitis by reducing HMGB1 and iNOS expression via the Nrf2/HO-1 pathway.

AIM: Edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one) is a free radical scavenger that has shown potent antioxidant, anti-inflammatory and neuroprotective effects in variety of disease models. In this study, we investigated whether edaravone produced neuroprotective actions in an infant mouse model of pneumococcal meningitis. METHODS: C57BL/6 mice were infected on postnatal d 11 by intracisternal injection of a certain inoculum of Streptococcus pneumoniae. The mice received intracisternal injection of 10 µL of saline containing edaravone (3 mg/kg) once a day for 7 d. The severity of pneumococcal meningitis was assessed with a clinical score. In mice with severe meningitis, the survival rate from the time of infection to d 8 after infection was analyzed using Kaplan-Meier curves. In mice with mild meningitis, the CSF inflammation and cytokine levels in the hippocampus were analyzed d 7 after infection, and the clinical neurological deficit score was evaluated using a neurological scoring system d 14 after infection. The nuclear factor (erythroid-derived 2)-like 2 knockout (Nrf2 KO) mice and heme oxygenase-1 knockout (HO-1 KO) mice were used to confirm the involvement of Nrf2/HO-1 pathway in the neuroprotective actions of edaravone. RESULTS: In mice with severe meningitis, edaravone treatment significantly increased the survival rate (76.4%) compared with the meningitis model group (32.2%). In mice with mild meningitis, edaravone treatment significantly decreased the number of leukocytes and TNF- levels in CSF, as well as the neuronal apoptosis and protein levels of HMGB1 and iNOS in the hippocampus, but did not affect the high levels of IL-10 and IL-6 in the hippocampus. Moreover, edaravone treatment significantly improved the neurological function of mice with mild meningitis. In Nrf2 KO or HO-1 KO mice with the meningitis, edaravone treatment was no longer effective in improving the survival rate of the mice with severe meningitis (20.2% and 53.6%, respectively), nor it affected the protein levels of HMGB1 and iNOS in the hippocampus of the mice with mild meningitis. CONCLUSION: Edaravone produces neuroprotective actions in a mouse model of pneumococcal meningitis by reducing neuronal apoptosis and HMGB1 and iNOS expression in the hippocampus via the Nrf2/HO-1 pathway. Thus, edaravone may be a promising agent for the treatment of bacterial meningitis.

[Analysis of the follow-up results concerning pregnancy, delivery and infants after assisted reproductive technique with GnRH-a for luteal support].

OBJECTIVE: To investigate the results of follow-up visits of pregnancy course, delivery and infants of women who got clinically pregnant by assisted reproductive technique after gonadotropin-releasing hormone agonist (GnRH-a) added for luteal support, and to analyse the influence of adding GnRH-a in luteal support on the safety of mother and infant. METHODS: A retrospective analysis was carried out on the medical record from 215 patients who got clinically pregnant after luteal phase long regimen fresh-cycle transfer was operated. According to the differences in luteal support methods, the patients were assigned to Group A (124 patients, progesterone+dydrogesterone group), Group B (91 patients, GnRH-a added group). The patients' pregnancy course, delivery time, and the growth and development of infants within 1-2 years were followed up. RESULTS: (1) There was no obvious difference between Group A and Group B in terms of the abortion ratio during the early pregnancy (8.1%, 12.1%), the rate of abortion villous deformity (50.0%, 9.1%), the rate of heterotopic pregnancy (10.5%, 5.5%) and rate of twin pregnancy (19.4%, 28.6%; all P>0.05). (2) Compared to group A, during the middle and late pregnancy of single or twin pregnancy in Group B , there was no obvious difference in the rate of fetal chromosomal abnormality, organ malformation incidence, late abortion rate and stillbirth rate (all P>0.05). (3) As to childbirth, in the case of twin pregnancy, there was a higher rate of premature delivery (60.0%, 39.1%; P=0.041), as well as rate of lower birth weight of newborn (56.0%, 34.8%; P=0.037) in group B. (4) The statistics on general growth and development as well as infantile common diseases within 2 years after birth indicated that there was no obvious difference between the two groups in single birth and twin birth subgroup (all P>0.05). CONCLUSION: On the basis of controlling of implanted embryos and reducing the occurrence of twins, GnRH-a luteal support maybe relatively safe and effective.

Lipopolysaccharides shapes the human Wharton's jelly-derived mesenchymal stem cells in vitro.

BACKGROUND: Although the expression of toll-like receptors (TLRs) on different types of human mesenchymal stem cells (hMSCs) has recently been reported, controversy remains regarding the presence of TLR4 as well as its engagement and impact on human Wharton's jelly-derived MSCs (hWJ-MSCs). METHODS: In the present study, the expression and role of TLR4 in hWJ-MSCs was investigated using a model of lipopolysaccharide (LPS). Proliferation, apoptosis, and the expression of paracrine factors in hWJ-MSCs primed with LPS were analysed. RESULTS: The expression of TLR4 was high at the RNA level but very low at the protein level. hWJ-MSCs responded to LPS stimulation and initiated a marked up-regulation of inflammatory cytokine (IL-1α, IL-1ß, IL-6, and IL-8) production. Moreover, hWJ-MSCs LPS stimulation resulted in the up-regulation of indoleamine 2,3-dioxygenase [IDO]-1, Cox2, interferon [IFN]-ß, and matrix metalloproteinase (MMP)-2 but a down-regulation of MMP-9, which affect the immunosuppressive potential of hWJ-MSCs. CONCLUSIONS: These data suggest that LPS engagement shapes hWJ-MSCs and results in the production of pro-inflammatory cytokines and inhibitory immune mediators, showing TLR4 agonist induces the hWJ-MSCs polarization to a pro-inflammatory and immunosuppressive state, which may be beneficial for the exploration of the clinical potential of hWJ-MSCs.

Association of VEGF gene polymorphisms with advanced retinopathy of prematurity: a meta-analysis.

Published data on the association of vascular endothelial growth factor (VEGF) gene polymorphisms with retinopathy of prematurity (ROP) are inconclusive. The aim of the study was to assess the association by using meta-analysis. Data were collected from the following electronic databases: PubMed, Elsevier Science Direct, Excerpta Medica Database, Cochrane Library and China National Knowledge Infrastructure, with the last report up to 30 April, 2012. The odds ratio (OR) and its 95 % confidence interval (95 %CI) were used to assess the strength of the association. Meta-analysis was performed in a fixed/random effect model by using the software Review Manager 4.2. A total of 7 studies based on the search criteria were involved in this meta-analysis. Meta-analysis was performed for four VEGF gene polymorphisms (-634G/C, -460T/C, -2578C/A and 936C/T). Significant association was found for -460T/C polymorphism (C vs T: OR = 0.74, 95 %CI = 0.57-0.95, P = 0.02; TC+CC vs TT: OR = 0.75, 95 %CI = 0.47-1.21, P = 0.24; CC vs TT+TC: OR = 0.45, 95 %CI = 0.26-0.76, P = 0.003; CC vs TT: OR = 0.45, 95 %CI = 0.24-0.84, P = 0.01; TC vs TT: OR = 0.96, 95 %CI = 0.59-1.57, P = 0.87) in the VEGF gene, but not for other polymorphisms (-634G/C, -2578C/A and 936C/T). This meta-analysis demonstrates that advanced ROP is associated with VEGF gene -460T/C polymorphism, but not -634G/C, -2578C/A and 936C/T.

Nomogram incorporating ultrasonic markers of endometrial receptivity to determine the embryo-endometrial synchrony after in vitro fertilization.

Background: A successful pregnancy using in vitro fertilization and embryo transfer (IVF-ET) requires a receptive endometrium, good-quality embryos, and a synchronized embryo-endometrial dialogue. Although embryo quality and endometrial receptivity (ER) have been fully assessed to exclude substandard conditions, the probability of successful ET is relatively low. Currently, embryo-endometrial synchrony is considered to be a possible explanation, because delayed, advanced, or narrowed window of implantation (WOI) may lead to ET failure. Objective: This study aims to establish a nomogram incorporating a series of ultrasonic ER markers on the day before implantation to assess the embryo-endometrial synchrony, which may contribute to the improvement of clinical pregnancy outcomes. Methods: Totally 583 women with 1135 complete IVF cycles were retrospectively analyzed. Among them, 357 women with 698 cycles and 226 women with 437 cycles were assigned to the training and validation cohorts, respectively. Ultrasonic ER markers obtained on the day before implantation were collected for analyses. In the training cohort, the screened correlates of clinical pregnancy failure were utilized to develop a nomogram for determining whether an infertile woman is suitable for the ET next day. This model was validated both in the training and validation cohorts. Results: Spiral artery (SA) resistance index (RI), vascularisation index (VI), and flow index (FI) were independently associated with the ET failure (all P < 0.05). They were served as the components of the developed nomogram to visualize the likelihood of implantation failure in IVF-ET. This model was validated to present good discrimination and calibration, and obtained clinical net benefits both in the training and validation cohorts. Conclusion: We developed a nomogram that included SA-RI, VI, and FI on the day before implantation. It may assist physicians to identify patients with displaced WOI, thus avoiding meaningless ET prior to implantation.

Analysis of the guidance value of 3D ultrasound in evaluating endometrial receptivity for frozen-thawed embryo transfer in patients with repeated implantation failure.

BACKGROUND: Repeated implantation failure (RIF) is currently believed by some scholars to be mainly related to the poor endometrial receptivity. Three-dimensional (3D) ultrasound, as a noninvasive examination, has attracted the most attention. This paper further discusses whether 3D ultrasound of the endometrial receptivity index has guidance value in the evaluation of pregnancy outcomes in patients with RIF following frozen-thawed embryo transfer. METHODS: A total of 79 patients with RIF were retrospectively analyzed. These 79 patients which were confirmed by the transvaginal ultrasonography detection comprised 36 cases of intrauterine pregnancy, which were included in the pregnancy group, and 43 cases with biochemical pregnancy (the HCG in blood or urine is only transient and can be detected by clinical biochemical methods. The pregnancy sac cannot be seen under ultrasound) or negative results of human chorionic gonadotropin (HCG) examination, which were included in the non-pregnancy group. The endometrial thickness, uterine volume, sub-endometrial blood flow type, pulsatility index (PI) and resistance index (RI) of the spiral artery; the RI and PI of the uterine artery; and the peak systolic velocity/end diastolic velocity (S/D) of the two groups were measured and analyzed. RESULTS: (I) There were no significant differences in the age, infertility years, body mass index (BMI), anti-Müllerian hormone (AMH), endometrial thickness on the hCG injection day, estradiol (E2), and progesterone (P) between the pregnant and non-pregnant groups (P>0.05). (II) There were no significant differences in the endometrial thickness, uterine volume, and RI and PI of the uterine artery on the day before the implantation between the two groups (P>0.05). (III) There was statistical difference in the sum of the S/D of the two uterine arteries between the two groups (P<0.05) with a cutoff value of 14.47 (P<0.05). (IV) The RI and PI of the spiral artery in the non-pregnancy group were lower than those in the pregnancy group, and the difference was statistically significant (P<0.05). (V) The differences in the endometrial classification and subendometrial blood flow classification between the two groups were statistically significant (P<0.05). CONCLUSIONS: Ultrasonographic endometrial blood flow classification, spiral artery blood flow parameters, and uterine artery blood flow parameters can be effective indexes for evaluating endometrial receptivity, and they have a certain clinical significance in evaluating the pregnancy outcome of RIF patients after retransplantation.

Neonatal outcomes of very preterm infants from a neonatal intensive care center.

BACKGROUND: Information about clinical outcomes of very preterm (VPT) infants in tertiary neonatal intensive care unit (NICU) setting is scant in China. This study aimed to investigate the mortality and morbidity of VPT infants admitted to BaYi Children's Hospital, which serves as a NICU referral center for the city of Beijing, China. METHODS: Retrospectively collected perinatal/neonatal data on all admissions of infants born at <32 weeks of gestational age and subsequently admitted to the VPTNICU from clinical records between October 2010 and September 2011. RESULTS: Totally 729 infants were identified. 90% of VPT infants were outborn. The overall survival of the infants to discharge was 92%, which increased with increasing gestational age (range from 69% at <28 weeks to 99% at 31 weeks). The incidence of bronchopulmonary dysplasia was 4%, retinopathy of prematurity requiring treatment 2%, intraventricular hemorrhage III-IV 6%, and periventricular leukomalacia 2%. 10% of the VPT infants had a major morbidity at discharge. CONCLUSIONS: The outcomes of the VTP infants at this referral NICU were comparable to those in tertiary centers in developed countries. The most common complications were lower than those in other cohorts. Accordingly, high-volume NICU may minimize the adverse effects of VPT infants' transport.

Neuroprotective effects of icariin on memory impairment and neurochemical deficits in senescence-accelerated mouse prone 8 (SAMP8) mice.

The senescence-accelerated mouse prone 8 (SAMP8) is a novel aging model characterized by early onset and rapid advancement of senescence. In the present study, 6-month-old male SAMP8 mice were orally administered icariin (75, 150mg/kg) for 15weeks. Mice were submitted to passageway water maze test and step-down passive avoidance test for evaluating cognitive impairments. The HPLC-EC technique was used to determine the monoamine contents in the brain. The effects of icariin on oxidative stress and the acetylcholinesterase (AChE) activity of SAMP8 mice were also investigated. We found that icariin treatment significantly prevented learning and memory impairments of SAMP8 mice in passageway water maze test and step-down test. Icariin could partly reverse alterations of monoamines and metabolites levels in the cortex and hippocampus of SAMP8 mice. Furthermore, icariin-treated SAMP8 mice had significantly decreased malondialdehyde (MDA), nitric oxide (NO) contents, lowered nitric oxide synthase (NOS) activity and higher glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities in the brain homogenates and serum. Meanwhile, the acetylcholinesterase activity was markedly inhibited after icariin administration. However, the positive control piracetam did not show significant beneficial effects. In conclusion, the present findings demonstrated that the improvement of icariin on cognitive impairments in SAMP8 mice may be due to increasing monoamines levels, inhibiting oxidative damage and decreasing acetylcholinesterase activity.