Single-etched fiber-chip coupler with a metal mirror on a 220-nm silicon-on-insulator platform for perfectly vertical coupling.

Vertical couplers play a pivotal role as essential components supporting interconnections between fibers and photonic integrated circuits (PICs). In this study, we propose and demonstrate a high-performance perfectly vertical coupler based on a three-stage inverse design method, realized through a single full etching process on a 220-nm silicon-on-insulator (SOI) platform with a backside metal mirror. Under surface-normal fiber placement, experimental results indicate a remarkable 3-dB bandwidth of 99 nm with a peak coupling efficiency of -1.44 dB at the wavelength of 1549 nm. This achievement represents the best record to date, to the best of our knowledge, for a perfectly vertical coupler fabricated under similar process conditions.

Co-exposure of microcystin and nitrite enhanced spermatogenic disorders: The role of mtROS-mediated pyroptosis and apoptosis.

Microcystins (MCs) and nitrites are coexisted in the environment and have reproductive toxicity. The combined toxic effect and mechanism of MCs and nitrite on spermatogenesis remain largely unclear. In the present study, co-exposure to microcystin-leucine arginine (MC-LR) and sodium nitrite (NaNO2) aggravated testicular damage of Balb/c mice and mitochondrial impairment of spermatogonia, Sertoli cells, and sperm. Furthermore, MC-LR and NaNO2 reduced sperm density with a synergistic effect. In addition, MC-LR and NaNO2 synergistically induced oxidative stress in the reproductive system by decreasing superoxide dismutase (SOD) activity and glutathione (GSH) levels and increasing levels of mitochondrial reactive oxygen species (mtROS) and reactive oxygen species (ROS). More importantly, mitoquidone mesylate (MitoQ), an inhibitor of mtROS, blocked MC-LR and NaNO2-induced spermatogonia and Sertoli cell apoptosis by inhibiting high expression of Bax, Fadd, Caspase-8, and cleaved-Caspase-3. On the other hand, MitoQ suppressed pyroptosis of Sertoli cells by inhibiting the expression of NLRP3, N-GSDMD, and cleaved-Caspase-1. Additionally, MitoQ alleviated co-exposure-induced sperm density reduction and organ index disorders in F1 generation mice. Together, co-exposure of MC-LR and NaNO2 can enhance spermatogenic disorders by mitochondrial oxidative impairment-mediated germ cell death. This study emphasizes the potential risks of MC-LR and NaNO2 on reproduction in realistic environments and highlights new insights into the cause and treatment of spermatogenic disorders.

The effect and mechanism of combined exposure of MC-LR and NaNO2 on liver lipid metabolism.

Microcystin-LR (MC-LR) and sodium nitrite (NaNO2) co-exist in the environment and are hepatotoxic. The liver has the function of lipid metabolism, but the impacts and mechanisms of MC-LR and NaNO2 on liver lipid metabolism are unclear. Therefore, we established a chronic exposure model of Balb/c mice and used LO2 cells for in vitro verification to investigate the effects and mechanisms of liver lipid metabolism caused by MC-LR and NaNO2. The results showed that after 6 months of exposure to MC-LR and NaNO2, the lipid droplets content was increased, and the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were raised in the liver (P < 0.05). Moreover, MC-LR and NaNO2 synergistically induced hepatic oxidative stress by decreasing total superoxide dismutase (T-SOD) activity and glutathione (GSH) levels and increasing malondialdehyde (MDA) content levels. In addition, the levels of Nrf2, HO-1, NQO1 and P-AMPK was decreased and Keap1 was increased in the Nrf2/HO-1 pathway. The key factors of lipid metabolism, SREBP-1c, FASN and ACC, were up-regulated in the liver. More importantly, there was a combined effect on lipid deposition of MC-LR and NaNO2 co-exposure. In vitro experiments, MC-LR and NaNO2-induced lipid deposition and changes in lipid metabolism-related changes were mitigated after activation of the Nrf2/HO-1 signaling pathway by the Nrf2 activator tertiary butylhydroquinone (TBHQ). Additionally, TBHQ alleviated the rise of reactive oxygen species (ROS) in LO2 cells induced by MC-LR and NaNO2. Overall, our findings indicated that MC-LR and NaNO2 can cause abnormal liver lipid metabolism, and the combined effects were observed after MC-LR and NaNO2 co-exposure. The Nrf2/HO-1 signal pathway may be a potential target for prevention and control of liver toxicity caused by MC-LR and NaNO2.

Real-time FPGA prototyping of Doppler frequency shift compensation using DSP-assisted automatic frequency control.

This Letter presents a real-time coherent receiver using digital signal processing (DSP)-assisted automatic frequency control (AFC) to compensate for the Doppler frequency shift (DFS). DFS compensation range of ±8 GHz and the frequency shifting rate of 33 MHz/s are demonstrated in an FPGA-based 2.5 Gbaud QPSK coherent optical system. The experimental results indicate that the scheme achieves a sensitivity of -47 dBm at a bit error rate (BER) of 2E-4. The power penalty induced by the DFS compensation is less than 1 dB.

Environmentally related microcystin-LR-induced ovarian dysfunction via the CCL2-CCR10 axis in mice ameliorated by dietary mulberry.

Microcystin-LR (MC-LR) is a reproductive toxin produced by cyanobacteria in the aquatic environment and can be ingested by humans through drinking water and the food chain, posing a threat to human reproductive health. However, the toxic mechanisms and prospective interventions for MC-LR-induced ovarian dysfunction at environmental doses are unknown. The mulberry fruit is a traditional natural product of plant origin, with various pharmacological effects, such as antioxidant and anti-inflammatory effects. Here, mice were exposed to MC-LR (10, 100 µg/L) in drinking water for 90 days, during which mice were gavage 600 mg/kg/week of mulberry fruit extract (MFE). It was found that MC-LR can accumulate in mouse ovaries, causing sexual hormone disturbance, inflammatory infiltration, and ovarian pathological damage. Results from RNA-seq were shown that CCL2, a chemokine associated with inflammatory response, was significantly increased in mouse ovary after MC-LR exposure. Further investigation revealed that MC-LR exposure aggravates apoptosis of granulosa cells via the CCL2-CCR10 axis-mediated Jak/Stat pathway. Importantly, MFE can significantly ameliorate these ovarian dysfunction phenotypes by inhibiting the activation of the CCL2-CCR10 axis. This study broadened new insights into the ovarian toxicity of MC-LR and clarified the pharmacological effects of mulberry fruit on ovarian function protection.

Cadmium negatively affects the growth and physiological status and the alleviation effects by exogenous selenium in silage maize (Zea mays L.).

Increasing soil cadmium (Cd) contamination is a serious threat to human food health and safety. In order to reduce Cd uptake and Cd toxicity in silage maize, hydroponic tests were conducted to investigate the effect of exogenous Cd on the toxicity of silage maize in this study. In the study, a combination of Cd (5, 20, 50, 80, and 10 µM) treatments was applied in a hydroponic system. With increasing Cd concentration, Cd significantly inhibited the total root length (RL), root surface area (SA), root volume (RV), root tip number (RT), and branching number (RF) of maize seedlings, which were reduced by 28.1 to 71.3%, 20.2 to 64.9%, 11.2 to 56.5%, 43.7 to 63.4%, and 38.2 to 72.6%, respectively. The excessive Cd accumulation inhibited biomass accumulation and reduced silage maize growth, photosynthesis, and chlorophyll content and activated the antioxidant systems, including increasing lipid peroxidation and stimulating catalase (CAT) and peroxidase (POD), but reduced the activity of superoxide dismutase (SOD) and ascorbate peroxidase (APX) in the root. Besides, selenium (Se) significantly decreased the Cd concentration of the shoot and root by 27.1% and 35.1% under Cd50, respectively. Our results reveal that exogenously applied Cd reduced silage maize growth and impaired photosynthesis. Whereas silage maize can tolerate Cd by increasing the concentration of ascorbate and glutathione and activating the antioxidant defense system, the application of exogenous selenium significantly reduced the content of Cd in silage maize.

Real-time low-complexity diversity combining algorithm for free space coherent optical communication systems over atmospheric turbulence channel.

A novel diversity combining scheme, in conjunction with the complex-valued decision-directed least mean square (CV-DD-LMS) algorithm, is evaluated, and a real-time experimental validation is presented. This proposed scheme employs the CV-DD-LMS algorithm to concurrently perform beam combination and carrier phase recovery (CPR), thereby effectively reducing the overall complexity of digital signal processing. Furthermore, in the numerical simulation, under a low signal-to-noise ratio (SNR), a scheme utilizing the CV-DD-LMS algorithm effectively avoids cycle slips (CS) and outperforms schemes employing independent CPR modules. We experimentally validate this novel scheme by implementing it on an FPGA in a real-time 2.5Gb/s QPSK diversity-receiving system with three inputs. The back-to-back sensitivity is assessed using static received optical power, while the dynamic performance is evaluated by employing variable optical attenuators (VOAs) to simulate a power fluctuation at a frequency of 100kHz. The result proves that the implementation of the CV-DD-LMS algorithm yields stable performance while effectively reducing computational complexity.

Satellite-to-ground optical downlink model using mode mismatching multi-mode photonic lanterns.

Photonics lanterns (PLs) provide an effective mode diversity solution to mitigate atmospheric turbulence interference in free-space optical communications (FSOC). This paper presents mode-mismatching multimode photonic lanterns (MM-PLs) for diversity receiver in satellite-to-ground downlink scenarios. Our study evaluates the coupling characteristics of the mode-selective PLs (MSPLs) and non-mode-selective PLs (NSPLs) for the influence of strong-to-weak turbulence and confirms that MSPLs outperform NSPLs under weak turbulence conditions. The research further explores the impact of fiber position error (FPE) on the spatial light-to-fiber coupling, including the optimal focal length deviation and lateral offset of receiving fiber devices. We have calculated and compared the coupling power and signal-to-noise ratio (SNR) of few-mode PLs (FM-PLs) and MM-PLs for various turbulence intensities. The results indicate that the optimal focal length tolerance, which corresponds to a decrease of approximately 1 dB in the average coupling power, is 2-3 m and 5-6 m for FM-PLs and MM-PLs, respectively. Furthermore, regardless of whether it is strong or weak turbulence, MM-PL exhibits a lateral offset tolerance exceeding 12 µm for a 0.5 dB drop in the mean coupled power, whereas the lateral offset tolerance of FM-PL is only 3 µm under weak turbulence. Additionally, the decrease in the average SNR of MM-PLs is gentle, only 0.67-1.16 dB at a 12 µm offset under weak turbulence, whereas there is a significant reduction of 6.50-8.49 dB in the average SNR of FM-PLs. These findings demonstrate the superiority of MM-PLs over FM-PLs in turbulence resistance and fiber position tolerance in the satellite-ground downlink.

Research advances in identification procedures of endocrine disrupting chemicals.

Endocrine disrupting chemicals (EDCs) are increasingly concerned substance endangering human health and environment. However, there is no unified standard for identifying chemicals as EDCs, which is also controversial internationally. In this review, the procedures for EDC identification in different organizations/countries were described. Importantly, three aspects to be considered in identifying chemical substances as EDCs were summarized, which were mechanistic data, animal experiments, and epidemiological information. The relationships between them were also discussed. To elaborate more clearly on these three aspects of evidence, scientific data on some chemicals including bisphenol A, 1,2-dibromo-4-(1,2 dibromoethyl) cyclohexane and perchlorate were collected and evaluated. Altogether, the above three chemicals were assessed for interfering with hormones and elaborated their health hazards from macroscopic to microscopic. This review is helpful for standardizing the identification procedure of EDCs.

Association between bisphenol A exposure and thyroid dysfunction in adults: a systematic review and meta-analysis.

The occurrence of thyroid dysfunction is affected by environmental factors, and BPA is a ubiquitous environmental pollutant with the potential to cause thyroid dysfunction. However, the limited epidemiological evidence shows an inconsistent association between BPA exposure and thyroid dysfunction. Therefore, the literature on the impact of BPA on thyroid was sorted and analyzed to study the relationship between BPA and adult thyroid function. The studies published on or before 23rd May 2022 from PubMed, Web of Science, and Scopus were collected analyzing the association between BPA exposure and the levels of thyroid hormones. The methodological quality of each study was assessed, the sensitivity analysis and subgroup analysis based on study population and gender were also performed, and publication bias was evaluated. A total of 2969 literature studies were retrieved. Based on inclusion and exclusion criteria, eleven studies were included. Our results showed that BPA concentration was negatively correlated with FT4 and TSH in males. Pooled correlation coefficients between BPA and FT4/TSH were -0.027 (95%CI = -0.030∼-0.024) and -0.058 (95%CI = -0.111∼-0.004). BPA concentration was positively correlated with FT4 in females, and the pooled correlation coefficient was 0.006 (95%CI = 0.003-0.008). The effects of BPA on thyroid hormone levels were significantly different between males and females. BPA may significantly decrease the levels of FT4 and TSH in males but increase the levels of FT4 in females. Considering the high heterogeneity among studies and the limited investigations into subgroups, the relationship between BPA exposure and thyroid dysfunction needs to be further investigated.

[Risk factors for recurrence after intravitreal anti-vascular endothelial growth factor injection for retinopathy of prematurity]. / çŽ»ç’ƒä½“è ”å† æ³¨å°„æŠ—è¡€ç®¡å† çš®ç”Ÿé•¿å› å­æ²»ç–—æ—©äº§å„¿è§†ç½‘è†œç— å¤å‘çš„å±é™©å› ç´ åˆ†æž.

OBJECTIVES: To investigate the efficacy of intravitreal anti-vascular endothelial growth factor (anti-VEGF) injection in the treatment of retinopathy of prematurity (ROP) and the risk factors for recurrence. METHODS: A retrospective analysis was performed on the medical data of 159 infants with ROP who were born in the First Affiliated Hospital of Zhengzhou University and underwent anti-VEGF treatment from January 2016 to December 2021. According to the presence or absence of recurrence within the follow-up period after initial anti-VEGF treatment, they were divided into a recurrence group with 24 infants and a non-recurrence group with 135 infants. The medical data were compared between the two groups, and a multivariate logistic regression analysis was used to investigate the risk factors for the recurrence of ROP after anti-VEGF treatment. RESULTS: After one-time anti-VEGF treatment, all 159 infants showed regression of plus disease. Recurrence was observed in 24 infants (15.1%) after anti-VEGF treatment, with a mean interval of (8.4±2.6) weeks from treatment to recurrence. The multivariate logistic regression analysis showed that preoperative fundus hemorrhage and prolonged total oxygen supply time were risk factors for the recurrence of ROP (P<0.05), while gestational hypertension was a protective factor (P<0.05). CONCLUSIONS: Intravitreal anti-VEGF injection is effective for ROP. Preoperative fundus hemorrhage and long duration of oxygen therapy may increase the risk of ROP recurrence, and further studies are needed to investigate the influence of gestational hypertension on the recurrence of ROP.

Real-time FPGA prototyping of a 15GBaud SP-16QAM coherent optical receiver with optimal interpolating for clock recovery and equalization.

We demonstrate a real-time coherent optical receiver based on a single field programmable gate array (FPGA) chip. To strike the balance between the performance and hardware resources, we use a clock recovery scheme using the optimal interpolation (OI). The performance and complexity of the OI-based scheme and the traditional schemes are compared and discussed via offline digital signal processing. And a real-time 15GBaud single-polarization 16QAM transmission experiment under different received optical power using the FPGA-based receiver is carried out to demonstrate the overall performance of different clock recovery and equalization schemes. The result proves that, compared to the traditional scheme with a cubic interpolator and a 7-tap equalizer, the optimal interpolator significantly lowers the utilization of LUT, CARRY8, and DSP48 by 35%, 50%, and 11%, respectively, and can work properly under a received optical power of -40dBm.

A new identity of microcystins: Environmental endocrine disruptors? An evidence-based review.

Microcystins (MCs) are widely distributed cyanobacterial toxins in eutrophic waters. At present, the endocrine-disrupting effects of MCs have been extensively studied, but whether MCs can be classified as environmental endocrine disruptors (EDCs) is still unclear. This review is aimed to evaluate the rationality for MCs as to be classified as EDCs based on the available evidence. It has been identified that MCs meet eight of ten key characteristics of chemicals that can be classified as EDCs. MCs interfere with the six processes, including synthesis, release, circulation, metabolism, binding and action of natural hormones in the body. Also, they are fit two other characteristics of EDC: altering the fate of producing/responding cells and epigenetic modification. Further evidence indicates that the endocrine-disrupting effect of MCs may be an important cause of adverse health outcomes such as metabolic disorders, reproductive disorders and effects on the growth and development of offspring. Generally, MCs have endocrine-disrupting properties, suggesting that it is reasonable for them to be considered EDCs. This is of great importance in understanding and evaluating the harm done by MCs on humans.

Ultracompact and ultralow-loss S-bends with easy fabrication by numerical optimization.

Ultra-longitudinal-compact S-bends with flexible latitudinal distances (d) are proposed and experimentally demonstrated with ultralow loss and fabrication-friendly structures by three steps based on numerical optimization. During the first step (curve optimization), insertion losses (ILs) of S-bends are significantly reduced by optimizing transition curves based on Bézier curves. During the second step (shape optimization), the ILs are further minimized by varying the widths of S-bends to increase optical confinement. In the third step (curvature optimization), considering ease of fabrication, an optimization of curvature radius is used to ensure that all feature sizes for the S-bends are larger than 200 nm. Simulation results show that for S-bends with footprints of 2.5× d µm2, the ILs are less than (0.19, 0.045, 0.18, 0.27) dB in a wavelength range of 1400-1700 nm when d is set as (3, 6, 9, 12) µm, respectively. Then, the S-bends of 2.5× 3 µm2 and 2.5× 12 µm2 are fabricated on a commercial 220-nm silicon-on-insulator (SOI) platform. Experimental results show that the ILs of both are less than 0.16 dB in a wavelength range of 1420-1630 nm. The lowest ILs are 0.074 dB and 0.070 dB, respectively. Moreover, in addition to the ultralow ILs and ease of fabrication, our design is flexible for designing S-bends with a flexible value of d, which makes our approach practical in large-scale photonic integrated circuits.

Performance investigation of the probability-aided maximum likelihood sequence detector for a probabilistic shaped 16-QAM system.

In this paper, for the first time, a probability-aided maximum-likelihood sequence detector (PMLSD) is experimentally investigated through a 64-GBaud probabilistic shaped 16-ary quadrature amplitude modulation (PS-16QAM) transmission experiment. In order to relax the impacts of PS technology on the decision module, a PMLSD decision scheme is investigated by modifying the decision criterion of maximum-likelihood sequence detector (MLSD) correctly. Meanwhile, a symbol-wise probability-aided maximum a posteriori probability (PMAP) scheme is also demonstrated for comparison. The results show that the PMLSD scheme outperforms the direct decision scheme about 1.0-dB optical signal to noise ratio (OSNR) sensitivity. Compared with symbol-wise PMAP scheme, PMLSD scheme can effectively relax the impacts of PS technology on the decision module and a more than 0.8-dB improvement in terms of OSNR sensitivity in back-to-back (B2B) case is obtained. Finally, we successfully transmit the PS-16QAM signals over a 2400-km fiber link with a bit error ratio (BER) lower than 1.00×10-3 by adopting the PMLSD scheme.

MicroRNA-122 overexpression promotes apoptosis and tumor suppressor gene expression induced by microcystin-leucine arginine in mouse liver.

Microcystin-leucine arginine (MC-LR), an important hepatoxin, has the effect of promoting hepatocarcinogenesis. MicroRNA-122 (miR-122), an important tumor suppressor in liver, plays an important role in promoting cell apoptosis. Previous studies found that the expression of miR-122 was reduced after MC-LR exposure in liver. In this study, C57BL/6 mice were exposed to saline, negative control agomir, and MC-LR with or without miR-122 agomir transfection. The results indicated that MC-LR promoted the expressions of tumor suppressor genes and decreased the expressions of anti-apoptotic proteins B cell lymphoma-2 (Bcl-2) and Bcl-2-like 2 (Bcl-w), causing hepatocyte apoptosis. Under MC-LR exposure, miR-122 agomir transfection could further increase the expressions of tumor suppressor genes and the release of cytochrome-c (Cyt-c) and decrease the expressions of Bcl-2 and Bcl-w. In conclusion, miR-122 reduction can mitigate MC-LR-induced apoptosis to a certain extent, which in turn, it is likely to have contributed to MC-LR-induced hepatocarcinogenesis.

Investigation of the low-complexity Hilbert FIR filter enhanced 112-Gbit/s SSB 16-QAM transmission with parallelized Kramers-Kronig reception over 1440-km SSMF.

The Hilbert transform links the log-magnitude and the phase of the field modulated signals as long as the minimum phase condition is satisfied in the Kramer-Kronig (KK) receiver. In discrete-time signal processing, the Hilbert transform is generally replaced by a finite impulse response (FIR) filter to reduce the computational complexity, that is the so-called Hilbert transform FIR (HT-FIR) filter. The performance of the HT-FIR filter is extremely important, as the in-band flatness, the ripple, the group delay, the Gibbs phenomenon, and the edge effect, which indeed impair the phase retrieval. Hence, we investigate four different HT-FIR filter schemes that are in the form of type III and type IV based on the frequency-domain (FD) sampling approach and the time-domain (TD) windowing function approach. Also, we analyze the performance for each filter under different digital upsampling scenarios and conclude that a trade-off between the reduced inter-symbol-interference (ISI) and the Gibbs phenomenon is essential to obtain an optimal sampling rate and an improved KK performance when the HT-FIR filter with a short length is adopted. The results show that the FD-based HT-FIR filter can relax the upsampling requirement while having a better in-band flatness and a lower edge effect. The experiment is conducted in the parallelized block-wise KK reception-based 112-Gbit/s SSB 16-QAM optical transmission system over a 1920-km cascaded Raman fiber amplifier (RFA) link to investigate the limit transmission performance of the practical KK receiver. The experimental results show that when the transmission distance is up to 1440-km, the BER of the FD-based HT-FIR filter can be lower than the soft decision-forward error correction (SD-FEC) threshold of 2 × 10-2 with only 3 samples per symbol (3-SPS) upsampling rate and 8 non-integer tap coefficients are used, while other TD-based HT-FIR filter schemes with a BER lower than the SD-FEC threshold require at least 4-SPS upsampling rate.

Ultra-compact X-shaped waveguide crossings with flexible angles based on inverse design.

When photonics integrated circuits (PICs) become more massive in scale, the area of chip can't be taken full advantage of with 2×2 waveguide crossings with a 90° intersection angle. Crossings with small angles would be a better idea to further improve the area utilization, but few works have researched 2×2 crossings with different angles. In this paper, in order to have an ultra-compact footprint and a flexible intersection angle while keeping a high performance, we report a series of compact X-shaped waveguide crossings in silicon-on-insulator (SOI) waveguides for fundamental transverse electric (TE0) mode, designed by using finite-difference frequency-domain (FDFD) numerical analysis method and a global optimization method. Thanks to inverse design, a compact footprint as small as 4.5 µm2 and various angles between two input/output waveguides of 30°, 45°, 60°, 80° and 90° are achieved. Simulation results show that all crossings have good performance of insertion losses (ILs) within 0.1∼0.3 dB and crosstalks (CTs) within -20∼-50 dB in the wavelength range of 1525∼1582 nm. Moreover, the designed crossings were fabricated on a commercially available 220-nm SOI platform. The measured results show that the ILs of all crossings are around 0.2∼0.4 dB and the CTs are around -20 dB∼-32 dB; especially for the 30° intersection angle, the crossing has IL around 0.2 dB and CT around -31 dB in C band. Besides, we theoretically propose an approach of a primary structure processing technique to enhance the device performance with a more compact footprint. This technique is to remove the redundant structures in conjunction with the electric field distribution during the optimization procedure of inverse design. For the new 90° crossing structure produced by it, simulation results show that ILs of 0.29 ± 0.03 dB and CTs of -37 ± 2.5 dB in the wavelength range of 1500∼1600 nm are achieved and the footprint is shrunk by 25.5%.

Advances in the toxicology research of microcystins based on Omics approaches.

Microcystins (MCs) are the most widely distributed cyanotoxins, which can be ingested by animals and human body in multiple ways, resulting in a threat to human health and the biodiversity of wildlife. Therefore, the study on toxic effects and mechanisms of MCs is one of the focuses of attention. Recently, the Omics techniques, i.e. genomics, transcriptomics, proteomics and metabolomics, have significantly contributed to the comprehensive understanding and revealing of the molecular mechanisms about the toxicity of MCs. This paper mainly reviews current literature using the Omics approaches to explore the toxicity mechanism of MCs in liver, gonad, spleen, brain, intestine and lung of multiple species. It was found that MCs can exert strong toxic effects on various metabolic activities and cell signal transduction in cell cycle, apoptosis, destruction of cell cytoskeleton and redox disorder, at protein, transcription and metabolism level. Meanwhile, it was also revealed that the alteration of non-coding RNAs (miRNA, circRNA and lncRNA, etc.) and gut microbiota plays an essential regulatory role in the toxic effects of MCs, especially in hepatotoxicity and reproductive toxicity. In addition, we summarized current research gaps and pointed out the future directions for research. The detailed information in this paper shows that the application and development of Omics techniques have significantly promoted the research on MCs toxicity, and it is also a valuable resource for exploring the toxic mechanism of MCs.

Polar coded probabilistic shaping PAM8 based on many-to-one mapping for short-reach optical interconnection.

In this paper, a polar coded probabilistic shaping (PS) 8-ary pulse amplitude modulation (PAM8) based on many-to-one (MTO) mapping is investigated for short-reach optical interconnection. By ingeniously assigning parity bits to ambiguities positions, no extra PS redundancy and no complex distribution matcher are required in the scheme comparing to traditional probabilistic amplitude shaping (PAS). The noise distributions after different transmission distances are studied and an optimal clock recovery method for PS signal is proposed to degrade the impact of severe eye skew effect on BER performance. The experimental results show that up to 1.2 dB and 0.8 dB shaping gains are respectively achieved over back-to-back (BTB) and 2-km standard single mode fiber (SSMF) transmission. With the help of the proposed optimal clock recovery method in the PS scheme, the shaping gain is improved from 0.15 dB to 0.4 dB after 10-km transmission. Moreover, compared to low-density parity-check (LDPC) code, the polar coded PS-PAM8 can provide an additional coding gain of 2.2 dB with code length of 256, which proves the performance superiority of polar code in short code length. Therefore, the proposed polar coded PS-PAM8 with low complexity and satisfactory BER performance is believed to be an alternative solution for the cost-sensitive short-reach optical interconnection.