5-Hydroxymethylcytosine signals in serum are a predictor of chemoresistance in high-grade serous ovarian cancer.

OBJECTIVE: The genome-wide profiling of 5-hydroxymethylcytosines (5hmC) on circulating cell-free DNA (cfDNA) has revealed promising biomarkers for various diseases. The purpose of this study was to investigate 5hmC signals in serum cfDNA and identify novel predictive biomarkers for the development of chemoresistance in high-grade serous ovarian cancer (HGSOC). We hypothesized that 5hmC profiles in cfDNA reflect the development of chemoresistance and elucidate pathways that may drive chemoresistance in HGSOC. Moreover, we sought to identify predictors that would better stratify outcomes for women with intermediate-sensitive HGSOC. METHODS: Women diagnosed with HGSOC and known platinum sensitivity status were selected for this study. Nano-hmC-Seal was performed on cfDNA isolated from archived serum samples, and differential 5hmC features were identified using DESeq2 to establish a model predictive of chemoresistance. RESULTS: A multivariate model consisting of three features (preoperative CA-125, largest residual implant after surgery, 5hmC level of OSGEPL), stratified samples from intermediate sensitive, chemo-naive women diagnosed with HGSOC into chemotherapy-resistant- and sensitive-like strata with a significant difference in overall survival (OS). Independent analysis of The Cancer Genome Atlas data further confirmed that high OSGEPL1 expression is a favorable prognostic factor for HGSOC. CONCLUSIONS: We have developed a novel multivariate model based on clinico-pathologic data and a cfDNA-derived 5hmC modified gene, OSGEPL1, that predicted response to platinum-based chemotherapy in intermediate-sensitive HGSOC. Our multivariate model applies to chemo-naïve samples regardless if the patint was treated with adjuvant or neoadjuvant chemotherapy. These results merit further investigation of the predictive capability of our model in larger cohorts.

Fast 3D positioning based on a simplified THz photonic stereo ISAR system.

In this work, a THz stereo inverse synthetic aperture radar scheme based on photonics is proposed, and proof-of-concept experimentally demonstrated, achieving high resolution and fast three-dimensional (3D) positioning of multiple targets. An optical frequency comb and a uni-traveling carrier photodiode are employed to photonically generate a linear frequency-modulation signal at 300-320 GHz. By two incoherent measurements at different angles with one pair of antennas, 3D positioning of plane reflectors over a distance of 0.6 m is successfully accomplished, achieving a resolution of 7.5 mm for both range and azimuth dimensions, and a maximum experimental height error of 4 mm.

Hesperetin promotes diabetic wound healing by inhibiting ferroptosis through the activation of SIRT3.

Hesperetin (HST) is a flavonoid compound naturally occurring in citrus fruits and is widespread in various traditional medicinal herbs such as grapefruit peel, orange peel, and tangerine peel. These plant materials are commonly used in traditional Chinese medicine to prepare herbal remedies. The study aimed to investigate the potential molecular mechanisms through which HST reduces ferroptosis in human umbilical vein endothelial cells (HUVECs) and promotes angiogenesis and wound healing. We employed network pharmacology to predict the downstream targets affected by HST. The expression of markers related to ferroptosis was assessed through Western blot (WB) and polymerase chain reaction. Intracellular levels of ferroptosis-related metabolism were examined using glutathione/oxidized glutathione (GSH/GSSG) and malondialdehyde (MDA) assay kits. Mitochondrial status and iron levels within the cells were investigated through staining with Mitosox, FerroOrange, and JC1 staining. Potential downstream direct targets of HST were identified using molecular docking. Additionally, wound healing and neovascularization within the wound site were analyzed using various methods including HE staining, Masson's staining, immunohistochemistry, and Doppler hemodynamics assessment. HST effectively inhibits the elevated levels of intracellular ferroptosis stimulated by ERASTIN. Furthermore, we observed that HST achieves this inhibition of ferroptosis by activating SIRT3. In a diabetic rat wound model, HST significantly promotes wound healing, reducing levels of tissue ferroptosis, consistent with our in vitro findings. This study demonstrates that HST can inhibit the progression of ferroptosis and protect the physiological function of HUVECs by activating SIRT3. HST holds promise as a natural compound for promoting diabetic wound healing.

Optical amplification-free deep reservoir computing-assisted high-baudrate short-reach communication.

An optical amplification-free deep reservoir computing (RC)-assisted high-baudrate intensity modulation direct detection (IM/DD) system is experimentally demonstrated using a 100G externally modulated laser operated in C-band. We transmit 112 Gbaud 4-level pulse amplitude modulation (PAM4) and 100 Gbaud 6-level PAM (PAM6) signals over a 200-m single-mode fiber (SMF) link without any optical amplification. The decision feedback equalizer (DFE), shallow RC, and deep RC are adopted in the IM/DD system to mitigate impairment and improve transmission performance. Both PAM transmissions over a 200-m SMF with bit error rate (BER) performance below 6.25% overhead hard-decision forward error correction (HD-FEC) threshold are achieved. In addition, the BER of the PAM4 signal is below the KP4-FEC limit after 200-m SMF transmission enabled by the RC schemes. Thanks to the use of a multiple-layer structure, the number of weights in deep RC has been reduced by approximately 50% compared with the shallow RC, whereas the performance is comparable. We believe that the optical amplification-free deep RC-assisted high-baudrate link has a promising application in intra-data center communications.

Ultrasensitive Anisotropic Room-Temperature Terahertz Photodetector Based on an Intrinsic Magnetic Topological Insulator MnBi2Te4.

Terahertz photodetectors based on emergent intrinsic magnetic topological insulators promise excellent performance in terms of highly sensitive, anisotropic and room-temperature ability benefiting from their extraordinary material properties. Here, we propose and conceive the response features of exfoliated MnBi2Te4 flakes as active materials for terahertz detectors. The MnBi2Te4-based photodetectors show the sensitivity rival with commercially available ones, and the noise equivalent power of 13 pW/Hz0.5 under 0.275 THz at room-temperature led by the nonlinear Hall effect, allowing for the high-resolution terahertz imaging. In addition, a large anisotropy of polarization-dependent terahertz response is observed when the MnBi2Te4 device is tuned into different directions. More interestingly, we discover an unprecedented power-controlled reversal of terahertz response in the MnBi2Te4-graphene device. Our results provide feasibility of manipulating and exploiting the nontrivial topological phenomena of MnBi2Te4 under a high-frequency electromagnetic field, representing the first step toward device implementation of intrinsic magnetic topological insulators.

Ultrafast visible-infrared photodetector based on the SnSe2/Bi2Se3 heterostructure.

Using the inherent properties of a heterostructure, ultrafast photodetectors with high sensitivity can be progressively developed that have the potential to carve a niche among the optoelectronic devices. In this Letter, a heterojunction photodetector based on SnSe2/Bi2Se3 is constructed, and a visible-infrared photoresponse with good sensitivity at room temperature is obtained. The SnSe2/Bi2Se3 photodetector demonstrates a high Iph/Id ratio of 1.2 × 104 at 0 V. Moreover, the high responsivity of 2.3 A/W, detectivity of 1.6 × 1011 Jones, and fast response time of 40 µs are simultaneously achieved. The presented results offer an alternative route for ultrafast photodetectors with high sensitivity.

Hybrid fiber-THz fronthaul supporting up to 16384-QAM-OFDM with the delta-sigma modulation.

With the progress of high-capacity radio access networks, ultra-dense small cells are rapidly being deployed in urban areas. As a result, the deployment of a large number of optical fibers in urban areas becomes a severe issue. In this Letter, we propose a hybrid fiber-terahertz (THz) mobile fronthaul system supporting flexible and high-order wireless signal transmission with the delta-sigma modulation. The photonic THz transmission is used as the seamless extension of fiber-based fronthaul in small cells. A 20-Gbit/s digital fiber-THz fronthaul system is experimentally demonstrated to validate the proposed scheme, with 10-km optical fiber transmission and 300-GHz wireless relay. Carrier aggregation of up to 10 40-MHz and 60-MHz 5G-new radio (5G-NR) channels at the radio carrier frequency of 3.9 GHz is reported. The design of quantization noise suppressed delta-sigma modulation enables the system to transmit orthogonal frequency division multiplexing (OFDM) modulation up to  16384 order quadrate amplitude modulation (QAM) mapping with the error vector magnitude (EVM) below 0.5%.

Human recognition with the optoelectronic reservoir-computing-based micro-Doppler radar signal processing.

Current perception and monitoring systems, such as human recognition, are affected by several environmental factors, such as limited light intensity, weather changes, occlusion of targets, and public privacy. Human recognition using radar signals is a promising direction to overcome these defects; however, the low signal-to-noise ratio of radar signals still makes this task challenging. Therefore, it is necessary to use suitable tools that can efficiently deal with radar signals to identify targets. Reservoir computing (RC) is an efficient machine learning scheme that is easy to train and demonstrates excellent performance in processing complex time-series signals. The RC hardware implementation structure based on nonlinear nodes and delay feedback loops endows it with the potential for real-time fast signal processing. In this paper, we numerically study the performance of the optoelectronic RC composed of optical and electrical components in the task of human recognition with noisy micro-Doppler radar signals. A single-loop optoelectronic RC is employed to verify the application of RC in this field, and a parallel dual-loop optoelectronic RC scheme with a dual-polarization Mach-Zehnder modulator (DPol-MZM) is also used for performance comparison. The result is verified to be comparable with other machine learning tools, which demonstrates the ability of the optoelectronic RC in capturing gait information and dealing with noisy radar signals; it also indicates that optoelectronic RC is a powerful tool in the field of human target recognition based on micro-Doppler radar signals.

Channel Model and Performance Analysis for MIMO Systems with Single Leaky Coaxial Cable in Tunnel Scenarios.

Due to the limited space in the tunnel environment, multiple-input multiple-output (MIMO) systems with double-port fed leaky coaxial cables (LCXs) can not only reduce the number of LCXs, but also improve the channel capacity. Based on the geometry based on single bonce (GBSB) and electromagnetic field radiation theory of LCX, a MIMO channel model with double-port fed LCX in a tunnel scenario is proposed in this paper. The channel impulse response (CIR) is derived, and verified with measurement results in terms of channel capacity. The distribution of channel capacity of single double-port fed LCX under different LCX lengths in the tunnel scenarios has also been analyzed in this work, and the distribution of channel capacity for the LCX-MIMO system with long LCX is predicted. The results show that the single double-port fed LCX-MIMO system outperforms the dipole antenna MIMO system with respect to channel capacity in the considered tunnel scenarios.

Photonic generation of terahertz dual-chirp waveforms ranging from 364 to 392†GHz.

In this paper, we propose and experimentally demonstrate a photonic scheme based on frequency doubling and photo-mixing to generate dual-chirp signals in the terahertz (THz) band. A broadband dual-chirp THz signal with 28 GHz bandwidth, ranging from 364 GHz to 392 GHz, is successfully generated in the proof-of-concept experiment, resulting in a chirp rate of 0.028 GHz/ns for both up chirp and down chirp signals. THz dual-chirp signals featuring a large bandwidth are beneficial to enable high resolution and high accuracy by mitigating the range measurement error induced by the range-Doppler coupling effect. Therefore, the proposed system is expected to have a great potential for future THz radar applications.

Nonlinearity-aware optoelectronic terahertz discrete multitone signal transmission with a zero-bias diode.

The terahertz band has been recognized as a promising candidate to support future rate-greedy applications such as 6G communications. Optoelectronic terahertz communications are beneficial for the realization of high-speed transmission. In this Letter, we propose and experimentally demonstrate an optoelectronic terahertz transmission system with intensity modulation and direct detection, where a discrete multitone (DMT) waveform with high-order quadrature amplitude modulation (QAM) is used. A zero-bias diode (ZBD) is used in the system as a simple, cost-effective direct detection terahertz receiver. A nonlinearity-aware digital signal reception routine is proposed to mitigate the nonlinear impairments induced by subcarrier-to-subcarrier beating interference from the ZBD. In this experiment, up to a 60 Gbit/s line rate 16QAM-DMT signal is successfully transmitted over a 3 m wireless link in the 310 GHz band, and the mean signal-to-noise ratio is improved by 3 dB with nonlinearity-aware signal processing routine. The advantageous features of such a scheme make it a promising solution for terahertz wireless communications.

The efficacy and safety of tranexamic acid in the treatment of intertrochanteric fracture: an updated meta-analysis of 11 randomized controlled trials.

This meta-analysis was performed to investigate the efficacy and safety of tranexamic acid (TXA) in the elderly patients undergoing intertrochanteric fracture surgery from the current literatures. The electronic literature database of PubMed, Embase and Cochrane library were searched in October 2019. The intraoperative blood loss, hidden blood loss, postoperative drainage and total blood loss, postoperative hemoglobin, length of stay, transfusion rate, mortality rate, thromboembolic events and wound complications were extracted. Stata 14.0 software was used for our meta-analysis. A total of 11 RCTs (3 new RCTs in 2019) with 1202 patients met our inclusion criteria. This meta-analysis showed that administration of TXA can reduce intraoperative blood loss (P = 0.009), hidden blood loss (P = 0.000), total blood loss (P = 0.000), length of stay (P = 0.003), transfusion rate (P = 0.000) and the occurrence of wound complications (P = 0.006). Furthermore, administration of TXA was associated with an increase in the postoperative Hb level at day 1, 2 and 3 (P = 0.000, P = 0.000 and P = 0.000, respectively) after surgery. However, no significant difference was found between the TXA group and control group regarding the occurrence of thromboembolic events (P = 0.978, including deep vein thrombosis, P = 0.850; pulmonary embolism, P = 0.788; cerebrovascular accident, P = 0.549; myocardial infarction, P = 0.395) and mortality rate (P = 0. 338). Our meta-analysis suggested that administration of TXA is effective in reducing intraoperative blood loss, hidden blood loss, total blood loss, length of stay, transfusion rate, wound complications and enhancing postoperative Hb without increasing the risk of thromboembolic events and mortality rate in intertrochanteric fracture surgery. More large multi-center and high-quality RCTs are required for further research.

Method of fiber transfer delay measurement based on phase quantization and delay synthesis.

A novel method, to the best of our knowledge, of fiber transfer delay (FTD) measurement based on phase quantization and delay synthesis is proposed and demonstrated. By detecting the differential phase shifts of a set of frequency-multiplied RF signals transmission through the fiber link with and without the FTD under the test, the ${2}\pi $2π phase ambiguity problem can be solved. To avoid the phase quantization error near the digital quantization boundary, a self-check and error-correction method is proposed so as to greatly improve the reliability of measurement. In the experiment, the measurement repeatability around 0.018 ps within a period of 80 s is achieved for a back-to-back fiber link, and a test resolution of 0.03 ps is proved with a motorized tunable delay line. The system is available for measurement of a large FTD range up to 100 µs with no dead zone.

Feasibility analysis of opto-electronic THz Earth-satellite links in the low- and mid-latitude regions.

Terahertz (THz) communication is considered as a promising technology for the Earth-space application due to its high potential of supporting large data capacity. However, THz wave suffers extreme attenuation from absorption of water vapor (WV) molecules in the propagation path. In this work, we present a theoretical model and analyze the capacities of both inter-satellite and geostationary satellite-to-Earth station (GEO-ES) opto-electronic links operating in the 100-500 GHz band within low- and mid-latitude regions. In our work, THz frequency windows in the 140, 220, 340, and 410 GHz bands with relatively low atmospheric loss are selectively used, targeting a data capacity of 10 Gbps per gigahertz. Our analysis indicates that, in the low-latitude regions, due to high water vapor density (WVD), transmitting and receiving antennas with extremely high gains are required. On the contrary, the mid-latitude regions require less power due to comparatively lower WVD. Moreover, due to seasonal variation in the mid-latitude regions, the requirement of link power budget is tens of decibels less in winter as compared to summer. The results suggest that the establishment of GEO-ES THz links in low- and mid-latitude regions is more realistic in the sub-THz bands, such as 140 and 220 GHz, while the potential of using higher carrier frequencies above 300 GHz for inter-satellite THz links, due to the absence of WV-induced absorption, is supported.

Tunable OEO-based photonic RF receiver with image frequency rejection.

A tunable optoelectronic oscillator (OEO)-based photonic radio frequency (RF) heterodyne receiver with the capability of image frequency rejection is proposed and experimentally demonstrated. The OEO incorporating a dual-electrode Mach-Zehnder modulator (DEMZM) operates as a high quality local oscillator (LO) and a broadband mixer simultaneously, with one electrode port of the DEMZM used for the feedback of the generated LO signal and the other port for receiving external RF signals. Two channels of immediate frequency (IF) signals can be achieved in optical domain by beating the +1-order sideband of LO with the +1-order sideband of input RFs and beating the -1-order sideband of LO with the -1-order sideband of input RFs correspondingly. Through setting the bias angle of the DEMZM at π/4 or 5π/4 and quadrature combining of the two channels of the IF signal, the combined IF signal down-converted from the target RF signal gets enhanced due to the in-phase sum of two channels, while the combined IF signal down-converted from the image frequency can be rejected due to out-of-phase sum of two channels. In the experiment, the input RF signals with operating frequency range from 8.85 to 14.85 GHz are successfully received with the image rejection ratio reaching 42.6 dB, and the spurious free dynamic range of the system is better than 94.8 dB Hz2/3.

Analysis of risk factors for loss of reduction after acromioclavicular joint dislocation treated with the suture-button.

BACKGROUND: The most commonly reported complication after acromioclavicular (AC) joint dislocation treated with the Suture-button is loss of reduction. Loss of reduction is a major factor influencing the patient's joint function and subjective satisfaction. The objective of this study is to analyze the risk factors causing loss of reduction after AC joint dislocation treated with the Suture-button. METHODS: One hundred and thirty patients with AC joint dislocation who were surgically treated the Suture-button in our hospital from February 2009 to February 2015, were recorded their age, sex, BMI, time from injury to surgery, Rockwood's classification, with or without osteoporosis, double or triple button technique, position of the clavicle tunnel, tunnel diameter, coracoid button position, alignment of the button, acromioclavicular ligament repair or not, different methods of postoperative limb immobilization, and so on. Mean comparisons or chi-square test was used for univariate analysis of the above factors, and then multivariate logistic regression analysis was performed to predict risk factors. RESULTS: Reduction was lost in 23.1% of the patients. Univariate analysis showed that button alignment, double or triple button technique, coracoid button position, position of the clavicle tunnel, acromioclavicular ligament repair or not and osteoporosis had statistically significant association with loss of reduction for AC joint (P = 0.031, 0.034, 0.000, 0.042, 0.047 and 0.000 respectively). Multivariate logistic regression analysis demonstrated that osteoporosis (P = 0.003), position of the clavicle tunnel (P = 0.032) and coracoid button position (P < 0.001) were the risk factors that significantly associated with the loss of reduction after AC joint dislocation treated with the Suture-button. CONCLUSIONS: Clavicle tunnel location using relative ratio method, accurate placement of button plate under coracoid process (inside or outside deviation <20°), various reinforcement operations for patients with osteoporosis are important factors in preventing loss of reduction.

Photonics-enabled compressive sensing with spectral encoding using an incoherent broadband source.

In this Letter, we propose an approach to achieving photonics-enabled compressive sensing of sparse wideband radio frequency signals in which an incoherent broadband source is applied, and the mixing and integration functions are realized in the optical domain. A spectrum shaper is employed to slice and encode the spectrum of the broadband light according to a predetermined random sequence. Because of the dispersion-induced group delay, the mixing between the incoming signal and the random bit sequence is achieved. At the output of the spectrum shaper, an array of photodetectors is employed to realize down-sampling, and the input sparse signal can be captured in a single-shot mode. Since no pulsed laser is employed, our scheme obviates the need for time-domain synchronization between the repetitive ultra-fast pulses and the random sequence. Experimental demonstrations and numerical results are presented to verify the feasibility and potential of the approach.

Highly sensitive demodulation of a vibration-induced phase shift based on a low-noise OEO.

A highly sensitive demodulation approach of a vibration-induced phase shift based on a low-noise optoelectronic oscillator (OEO) is proposed and experimentally demonstrated. The vibration-induced optical phase variation is directly converted to the electrical oscillating signal of the OEO with carrier phase-shifted double-sideband (CPS-DSB) modulation, which is realized by cascading a dual-output Mach-Zehnder modulator (DOMZM) and a fiber interferometer. Theoretically, within a CPS-DSB modulated OEO, the minimum detectable optical phase shift is determined by the phase noise achievable, and the sensitivity of the optical phase shift demodulation no longer depends on its frequency. A proof-of-concept OEO oscillating at 100 MHz with ultralow phase noise is built for demonstration. The achieved minimum detectable optical phase shift is 0.58 µrad/√Hz at 1 kHz and 0.21 µrad/√Hz at 10 kHz, which are the best results ever reported, to the best of our knowledge.

Experimental generation of linearly chirped 350 GHz band pulses with a bandwidth beyond 60 GHz.

We present in this Letter the experimental generation of linear frequency modulated (LFM) terahertz pulses with large bandwidths by using an optical interferometer-based photonic scheme and cutting-edge terahertz transceiver technology. The LFM pulses exhibiting a bandwidth in excess of 60 GHz centered at 350 GHz are successfully generated in the experiment, which represents the first demonstration of large time-bandwidth products (TBWPs) in the terahertz region above 300 GHz, to the best of our knowledge. The achieved TBWP of up to 527 has great potential in many prospective applications such as high-resolution radar sensing and imaging.

Frequency-dependent noise figure analysis of continuous photonic time-stretch system.

In this paper, the frequency-dependent noise figure of a continuous photonic time-stretch system is theoretically analyzed and experimentally demonstrated. Mathematic analysis discloses that the frequency-dependent noise figure in the continuous photonic time-stretch system is mainly owing to the dispersion-induced phase shift in the link. In the experiment, a completely continuous signal is reconstructed with time-interleaved joining of four sections of time-stretched signals from optical wavelength-division de-multiplexing channels. The result of the frequency-dependent noise figure property agrees well with that of theoretical analysis.