Real-time demonstration of a low-complexity PS scheme for 16QAM-DMT signals in an IM-DD system.

We experimentally demonstrated a low-complexity probabilistic shaping (PS) 16-ary quadrature amplitude modulation (16QAM) scheme based on intra-symbol bit-weighted distribution matching (Intra-SBWDM) for discrete multi-tone (DMT) symbols with field-programmable gate array implementation in an intensity modulation and direct detection (IM-DD) system. Different from the traditional PS scheme such as Gallager many-to-one mapping, hierarchical distribution matching and constant composition distribution matching, the Intra-SBWDM scheme with lower computation and hardware complexity does not need to continuously refine the interval to find the target symbol probability, nor does it need a look-up table, so it does not introduce a large number of extra redundant bits. In our experiment, four PS parameter values (k = 4, 5, 6, and 7) are investigated in a real-time short-reach IM-DD system. 31.87-Gbit/s net bit PS-16QAM-DMT (k = 4) signal transmission is achieved. The results show that the receiver sensitivity in terms of the received optical power of the real-time PS scheme based on Intra-SBWDM (k = 4) over OBTB/20 km standard single-mode fiber can be improved by about 1.8/2.2 dB at the bit error rate (BER) of 3.8 × 10-3, compared to the uniformly-distributed DMT. In addition, the BER is steadily lower than 3.8 × 10-3 during a one-hour measurement for PS-DMT transmission system.

Sparse I/Q-joint DNN nonlinear equalization based on progressive pruning for a photonics-aided 256-QAM MMW communication system.

An efficient nonlinear equalizer based on the pruning I/Q-joint deep neural network (DNN) is proposed and experimentally demonstrated to mitigate the nonlinearity in a photonics-assisted millimeter-wave (MMW) system with a high-order 256 quadrature-amplitude-modulation (QAM) format. Experimental findings reveal that implementing pruning on the I/Q-joint DNN can compress the computational overhead by 32% while accommodating 256-QAM E-band MMW transmission for a net throughput of 66.67 Gbps with 20.21% less complexity than the traditional Volterra nonlinear equalizer. Compared with the I/Q dual DNN with the same complexity, a 16% pruning ratio improvement is enabled by a robust pruning I/Q-joint DNN that further deciphers the I/Q relationship.

65,536-QAM OFDM signal transmission over a fiber-THz system at 320†GHz with delta-sigma modulation.

The transmission of a 65,536-ary quadrature amplitude modulation (QAM) orthogonal frequency division multiplexing (OFDM) signal supported by a hybrid fiber-terahertz (THz) multiple-input multiple-output (MIMO) system at 320 GHz is experimentally demonstrated in this Letter. We adopt the polarization division multiplexing (PDM) technique to double the spectral efficiency. Based on a 23-GBaud 16-QAM link, 2-bit delta-sigma modulation (DSM) quantization enables 65,536-QAM OFDM signal transmission over a 20-km standard single-mode fiber (SSMF) and a 3-m 2 × 2 MIMO wireless delivery, and satisfies the hard-decision forward error correction (HD-FEC) threshold of 3.8 × 10-3, corresponding to a net rate of 60.5 Gbit/s for THz-over-fiber transport. Meanwhile, below the fronthaul error vector magnitude (EVM) threshold of 0.34%, a maximum signal-to-noise ratio (SNR) of 52.6 dB is achieved. To the best of our knowledge, this is the highest modulation order achievable for DSM applications in THz communication.

SNR improved digital-delta-sigma-modulation radio-over-fiber scheme for D-band 4.6-km photonics-aided wireless fronthaul.

We propose a digital-delta-sigma-modulation radio-over-fiber (DDSM-RoF) scheme for wireless fronthaul and validate it experimentally in a D-band photonics-aided RoF transmission system. The 10-Gbaud DDSM-RoF signal with a common public radio interface equivalent data rate (CPRI-EDR) of 55.8 Gb/s is successfully transmitted in a 130-GHz 4.6-km wireless channel. The spectral efficiency (SE) is 5.58 bit/s/Hz and the capacity-distance product reaches 257 Gb/s·km. Up to 34.4-dB recovered signal-to-noise ratio (SNR) is observed to support the 1024-quadrature-amplitude-modulation (1024-QAM) transmission. Compared with the digital-analog-RoF (DA-RoF) scheme, the proposed DDSM-RoF achieves an SNR improvement of 5.9 dB.

The Jinggangmycin-induced Mthl2 gene regulates the development and stress resistance in Nilaparvata lugens Stål (Hemiptera: Delphacidae).

Methuselah (Mth) belongs to the GPCR family B, which regulates various biological processes and stress responses. The previous transcriptome data showed jinggangmycin (JGM)-induced Mthl2 expression. However, its detailed functional role remained unclear in brown planthopper, Nilaparvata lugens Stål. In adult N. lugens, the Mthl2 gene showed dominant expressions, notably in ovaries and fat body tissues. The 3rd instar nymphs treated with JGM increased starvation, oxidative stress, and high temperature (34 °C) tolerance of the adults. On the contrary, under dsMthl2 treatment, completely opposite phenotypes were observed. The lipid synthesis genes (DGAT1and PNPLA3) of both females and males treated with JGM in the nymphal stage were observed with high expressions, while the lipolysis of the Lipase 3 gene was observed with low expressions. The JGM increased triglyceride (TG) content, fat body droplet size, and the number of fat body droplets. The same treatment also increased the Glutathione S-transferase (GST), catalase (CAT), and superoxide dismutase (SOD) activities. An increase in the heat shock protein (HSP70 and HSP90) expression levels was also observed under JGM treatment but not dsMthl2. The current study demonstrated the influential role of the Mthl genes, particularly the Mthl2 gene, in modulating the growth and development and stress-responsiveness in N. lugens. Thus, providing a platform for future applied research programs controlling N. lugens population in rice fields.

Preoperative Biometric Parameters Predict the Vault after ICL Implantation: A Retrospective Clinical Study.

PURPOSE: To investigate the correlation between the preoperative biometric parameters of the anterior segment and the vault after implantable Collamer lens (ICL) implantation via this retrospective study. DESIGN: Retrospective clinical study. METHODS: A total of 78 eyes from 41 patients who underwent ICL implantation surgery were included in this study. Preoperative biometric parameters, including white-to-white (WTW) diameter, central corneal thickness, keratometer, pupil diameter, anterior chamber depth, sulcus-to-sulcus diameter, anterior chamber area (ACA) and central curvature radius of the anterior surface of the lens (Lenscur), were measured. Lenscur and ACA were measured with Rhinoceros 5.0 software on the image scanned with ultrasound biomicroscopy (UBM). The vault was assessed by UBM 3 months after surgery. Multiple stepwise regression analysis was employed to identify the variables that were correlated with the vault. RESULTS: The results showed that the vault was correlated with 3 variables: ACA (22.4 ± 4.25 mm2), WTW (11.36 ± 0.29 mm) and Lenscur (9.15 ± 1.21 mm). The regressive equation was: vault (mm) = 1.785 + 0.017 × ACA + 0.051 × Lenscur - 0.203 × WTW. CONCLUSIONS: Biometric parameters of the anterior segment (ACA, WTW and Lenscur) can predict the vault after ICL implantation using a new regression equation.

Conductive keratoplasty for symptomatic presbyopia following monofocal intraocular lens implantation.

BACKGROUND: To evaluate the visual outcomes of conductive keratoplasty for relief of symptomatic presbyopia of pseudophakia with monofocal intraocular lens implantation. DESIGN: It was a prospective clinical study and set in Eye Center, Second Affiliated Hospital, Zhejiang University. PARTICIPANTS: This study comprised 27 eyes from 27 patients with presbyopia symptom. METHODS: The patients received conductive keratoplasty via monovision approach after monofocal intraocular lens implantation and were followed up at 1 week and 1, 3, 6 and 12 months postoperatively. MAIN OUTCOME MEASURES: The main outcomes including uncorrected near visual acuity, uncorrected distance visual acuity, best spectacle-corrected visual acuity, manifest refraction spherical equivalent, keratometric astigmatism, contrast and glare sensitivity, spherical aberration and pseudoaccommodation were evaluated. RESULTS: Twelve months after conductive keratoplasty, the binocular uncorrected near visual acuity was significantly improved from logMAR 0.88 ± 0.16 preoperatively to logMAR 0.30 ± 0.13 (P < 0.05); the binocular uncorrected distance visual acuity and best spectacle-corrected visual acuity remained unchanged; manifest refraction spherical equivalent was significantly reduced from 0.01 ± 0.68 D preoperatively to -1.68 ± 0.39 D (P < 0.05); spherical aberration was increased from 0.266 ± 0.204 µm preoperatively to 0.358 ± 0.277 µm (P < 0.05), and pseudoaccommodation was from 1.38 ± 0.38 D to 1.73 ± 0.61 D (P < 0.05). CONCLUSIONS: Conductive keratoplasty is a safe and effective method for relief of symptomatic presbyopia of pseudophakia with monofocal intraocular lens implantation.

Endostar, a recently introduced recombinant human endostatin, inhibits proliferation and migration through regulating growth factors, adhesion factors and inflammatory mediators in choroid-retinal endothelial cells.

Retinal neovascularization is one of the leading causes for complete blindness in a number of diseases around the world. Endostar, a recently introduced recombinant human endostatin, has been considered as one of the most valuable anti-angiogenic agents. In this study, we demonstrate that Endostar inhibits both the proliferation of the choroid-retinal endothelial cells through limiting the progression of the cell cycle and their migration. Furthermore, Endostar induces the expression of the pigment epithelial-derived factor (PEDF) and suppresses the expression of the vascular endothelial growth factor (VEGF) and the fibroblast growth factor (FGF). Endostar also reduces the expression of the inflammatory mediator tumor necrosis factor-alpha (TNF-alpha), matrix metalloproteinases (MMPs) and vascular cell adhesion molecule-1 (VCAM-1). These findings reveal an integrated role of Endostar in the program of retinal vascular control and highlight its significant potential for broad clinical application.

Artisan iris-fixated intraocular lens implantation in combination with pupilloplasty-correction of aphakia with pathologically large pupil and insufficient capsular support.

OBJECTIVE: The aim of this study was to report the efficacy and safety of applying pupilloplasty in combination with Artisan iris-fixated intraocular lens (IOL) implantation in the treatment for aphakia with pathologically large pupil and insufficient capsular support. DESIGN: The study was a retrospective case series. PARTICIPANTS: Twenty-six aphakic eyes with pathologically large pupil and insufficient capsular support (from 26 patients) were included in the study. METHODS: The study patients underwent pupilloplasty in combination with Artisan iris-fixated IOL implantation. Follow-up appointments were scheduled at 1 week and at 1, 3, and 6 months postoperatively. RESULTS: The mean uncorrected visual acuity was significantly improved from logMAR 1.15 ± 0.29 to logMAR 0.37 ± 0.17, and the mean manifest refraction spherical equivalent was significantly decreased from 12.07 ± 2.20 D to -0.69 ± 0.70 D at 6 month after surgery (p < 0.05). The pupil diameter decreased significantly, from 5.7 ± 1.1 mm preoperatively to 4.5 ± 0.8 mm at 6 months after pupilloplasty (p < 0.05). Patients experienced less photophobia postoperatively. The safety parameters, including endothelial cell count, intraocular pressure, corneal astigmatism, best-corrected visual acuity, and central corneal thickness, showed no significant differences in values before and after surgery. CONCLUSIONS: The Artisan iris-fixated IOL implantation in combination with pupilloplasty can be used as an alternative way to correct aphakia with pathologically large pupil and insufficient capsular support.

Elevated preoperative HMGB1 as predictor of myocardial injury post-percutaneous coronary intervention.

In this study, we evaluated the impact of preoperative high mobility group box 1 (HMGB1) on myocardial injury post-percutaneous coronary intervention.We evaluated 302 consecutive patients who underwent percutaneous coronary intervention. They were divided into equal tertiles based on their preoperative HMGB1 levels. Creatine kinase-MB and troponin I levels were measured at baseline, 8- and 24-hours after the procedure, while clinical outcomes were followed up for 1 year.The occurrence of post-procedural myocardial injury was significantly higher in the tertile comprising of patients with elevated HMGB1 levels. Moreover, these patients showed significantly higher post-procedural peak values of creatine kinase-MB and troponin I in comparison to patients with lower HMGB1 levels. Event-free survival was significantly associated with HMGB1 levels, with worst event-free survival in patients with elevated HMGB1 levels.Elevated preoperative HMGB1 was a predictor of myocardial injury after percutaneous coronary intervention, and was associated with the worst clinical outcomes during 1-year follow up.

Implantable collamer lens versus iris-fixed phakic intraocular lens implantation to correct myopia: a meta-analysis.

This study is a meta-analysis comparing the efficacy, predictability, and safety of correcting myopia via implantation of two types of phakic intraocular lens (PIOLs): the implantable collamer lens (ICL) and iris-fixed PIOL. The Cochrane library, Pubmed, and EMBASE were searched. Study selection, data exclusion, and quality assessment were performed by two independent observers. The pooled relative risk (RR), pooled standardized mean difference (SMD), and their 95% confidence intervals (CIs) were used to compare lenses. Seven studies, involving 511 eyes, were included. The pooled SMD in postoperative uncorrected distance visual acuity (UDVA) comparing ICLs to iris-fixed PIOLs was -0.22 (95% CI, -0.58 to 0.13; P = .22). The pooled RR values of UDVA of 20/20 or better and of 20/40 or better comparing ICLs to iris-fixed PIOLs were 1.15 (95% CI, 0.89 to 1.47; P = .29) and 1.01 (95% CI, 0.95 to 1.08; P = .75), respectively. The pooled RR of loss of best spectacle-corrected visual acuity (BSCVA) and gain in BSCVA comparing ICLs to iris-fixed PIOLs were 1.20 (95% CI, 0.24 to 6.00; P = .82) and 1.14 (95% CI, 0.89 to 1.48; P = .31), respectively. The pooled RR comparing ICLs to iris-fixed PIOLs was 0.78 (95% CI, 0.29 to 2.12; P = .63) for all reported complications and 2.80 (95% CI, 1.04 to 7.52; P = .04) for severe complications. The pooled RR of achieving a result within ± 0.5 D (diopter) of the intended target comparing ICLs to iris-fixed PIOLs was 1.35 (95% CI, 1.04 to 1.77; P = .03). Overall, there is no significant difference in efficacy between the two types of PIOLs or in safety, except that the ICL is associated with a greater incidence of severe complications, especially anterior subcapsular cataract, primarily in the Version 2 and Version 3 groups. However, ICL has better predictability.

Conductive keratoplasty: an approach for the correction of residual hyperopia in post-lasik pseudophakia.

Although there are many formulae for the calculation of intraocular lens power in the eyes with previous kerato-refractive surgeries, unexpected refractive bias still exists. Hyperopic bias is particularly disliked because it affects both uncorrected distance and near visual acuity. Surgical treatment of the residual hyperopia for the eyes with both laser in situ keratomileusis and cataract surgery remains to be a big problem. Conductive keratoplasty has been shown to be an effective, safe and predictable method for low and moderate hyperopia in the pseudophakic eyes or in the eyes with kerato-refractive surgeries. However, the efficacy and safety of conductive keratoplasty in the correction of residual hyperopia after both corneal and lens refractive surgeries has not been reported. Herein, we reported the surgical correction with conductive keratoplasty for cases of residual hyperopia with/without astigmatism after previous laser in situ keratomileusis for high myopia and following phacoemulsification combined with posterior intraocular lens implantation for complicated cataract.

Correction of extreme hyperopia: artisan iris-fixated intraocular lens implantation for pseudophakia after clear lens extraction.

A 22-year-old patient suffering from both-side extreme hyperopia with amblyopia was corrected with an Artisan iris-fixated intraocular lens (IOL) implantation followed to clear lens extraction (CLE) with posterior chamber (PC)-IOL implantation. The preoperative refraction values were +17.75DS -1.50DC × 168° for the right eye and +17.25DS -0.75DC × 8° for the left eye. The uncorrected visual acuity (UCVA) was 20/200 bilaterally and the spectacle-corrected visual acuity (BSCVA) was 20/50 bilaterally. One year after Artisan iris-fixated IOL implantation, bilateral BSCVA was 20/50 with a refraction of +1.25DS -0.75DC × 13° for the right eye and +1.50DS -1.00DC × 55° for the left eye. The outcomes of an Artisan iris-fixated IOL implantation followed to CLE with PC-IOL implantation were encouraging for the correction of extreme hyperopia. Long term follow-up examinations were necessary for further determination of the efficacy and safety of this combinational procedure.