Volitional modulation of neuronal activity in the external globus pallidus by engagement of the cortical-basal ganglia circuit.

Volitional modulation of neural activity is not confined to the cortex but extends to various brain regions. Yet, it remains unclear whether neurons in the basal ganglia structure, the external globus pallidus (GPe), can be volitionally controlled. Here, we employed a volitional conditioning task to compare the volitional modulation of GPe and primary motor cortex (M1) neurons as well as the underlying circuits and control mechanisms. The results revealed that the volitional modulation of GPe neuronal activity engaged both M1 and substantia nigra pars reticulata (SNr) neurons, indicating the involvement of the cortex-GPe-SNr loop. In contrast, the volitional modulation of M1 neurons primarily occurred through the engagement of M1 local circuitry. Furthermore, lesioning M1 neurons did not affect the volitional learning or volitional control signal in GPe, whereas lesioning of GPe neurons impaired the learning process for the volitional modulation of M1 neuronal activity at the intermediate stage. Additionally, lesion of GPe neurons enhanced M1 neuronal activity when performing the volitional control task without reward delivery and a random reward test. Taken together, our findings demonstrated that GPe neurons could be volitionally controlled by engagement of the cortical-basal ganglia circuit and inhibit learning process for the volitional modulation of M1 neuronal activity by regulating M1 neuronal activity. Thus, GPe neurons can be effectively harnessed for independent volitional modulation for neurorehabilitation in patients with cortical damage. KEY POINTS: The cortical-basal ganglia circuit contributes to the volitional modulation of GPe neurons. Volitional modulation of M1 neuronal activity mainly engages M1 local circuitry. Bilateral GPe lesioning impedes volitional learning at the intermediate stages. Lesioning of GPe neurons inhibits volitional learning process by regulating M1 neuronal activity.

Analysis of the incidence and mortality trends of esophageal cancer in cancer registry areas of China and Japan.

This study aims to analyze the prevalence trend of esophageal cancer in Japan and China to provide suggestions for the prevention and treatment of esophageal cancer. The results showed that the incidence rate for the years 2010-2018 significantly decreased with an APC of 5.66%, and the mortality rate from 2010 to 2015 had an APC of -5.87% in China. However, the incidence rate of Japanese women showed an upward trend, with an APC of 4.09% from 2010 to 2019. The mortality rate of esophageal cancer in Japan showed a downward trend, with an APC of -2.96% from 2010 to 2021. From 2010 to 2018, Chinese esophageal squamous cell carcinoma accounted for the highest proportion, accounting for 85.96%, with the largest distribution in the middle, accounting for 47.25%. Patients are mostly diagnosed at stage III, and the relative survival rate from 2012 to 2015 was 30.3%. Japan also has the highest proportion of squamous cell carcinoma, and the lesions are also mostly located in the middle segment. While Japanese esophageal cancer patients are mostly diagnosed at stage I, and the relative survival rate was 41.5% in Japan from 2009 to 2011. The results of this article indicate that the current prevalence of esophageal cancer in China and Japan is generally declining, and the quality of life of patients is gradually improving, but effective screening and prevention strategies are still needed to reduce the burden of this disease.

Turbulence-resistant free space optical communication via chaotic block-matching and 3D filtering.

In this paper, we propose a chaotic block-matching and three-dimensional (C-BM3D) filtering algorithm to remove the noise and enhance the security in the turbulent channel of free space optical (FSO) communication. We experimentally demonstrate the performance of C-BM3D by comparing it with chaotic non-local means filtering (C-NLM), chaotic Gaussian filtering and chaotic Median filtering based on Log-normal and Gamma-Gamma turbulence models. The results show that the peak signal-to-noise ratios (PSNRs) of C-BM3D in the weak turbulence under Log-normal and Gamma-Gamma models are up to 96.2956 and 93.2853, respectively. The C-BM3D also achieves superior image similarity in Log-normal turbulent channel, with its structural similarity index measures (SSIMs) nearly equal to 1. Additionally, the signal-to-noise ratio (SNR) of C-BM3D ranks the highest, and its bit error rate (BER) improves by at least 15 dB compared to that of the other three algorithms. The experimental results indicate that the C-BM3D can be a good candidate for the next generation of FSO communication in security and turbulence resistance.

Spray-lithography of hybrid graphene-perovskite paper-based photodetectors for sustainable electronics.

Paper is an ideal substrate for the development of flexible and environmentally sustainable ubiquitous electronic systems. When combined with nanomaterial-based devices, it can be harnessed for various Internet-of-Things applications, ranging from wearable electronics to smart packaging. However, paper remains a challenging substrate for electronics due to its rough and porous nature. In addition, the absence of established fabrication methods is impeding its utilization in wearable applications. Unlike other paper-based electronics with added layers, in this study, we present a scalable spray-lithography on a commercial paper substrate. We present a non-vacuum spray-lithography of chemical vapor deposition (CVD) single-layer graphene (SLG), carbon nanotubes (CNTs) and perovskite quantum dots (QDs) on a paper substrate. This approach combines the advantages of two large-area techniques: CVD and spray-coating. The first technique allows for the growth of SLG, while the second enables the spray coating of a mask to pattern CVD SLG, electrodes (CNTs), and photoactive (QDs) layers. We harness the advantages of perovskite QDs in photodetection, leveraging their strong absorption coefficients. Integrating them with the graphene enhances the photoconductive gain mechanism, leading to high external responsivity. The presented device shows high external responsivity of ∼520 A W-1at 405 nm at <1 V bias due to the photoconductive gain mechanism. The prepared paper-based photodetectors (PDs) achieve an external responsivity of 520 A W-1under 405 nm illumination at <1 V operating voltage. To the best of our knowledge, our devices have the highest external responsivity among paper-based PDs. By fabricating arrays of PDs on a paper substrate in the air, this work highlights the potential of this scalable approach for enabling ubiquitous electronics on paper.

Atomized inhalation of Icaritin reduces airway inflammation and remodeling in asthmatic mice.

BACKGROUND: Asthma is a disease characterized by airway hyperresponsiveness and airway inflammation. Icaritin (ICT) is a plant hormone with various pharmacological activities such as anti-inflammatory, immune regulation, and anti-tumor. This study mainly explored the effects of nebulized inhalation of ICT on airway inflammation and airway remodeling in asthmatic mice. METHOD: Different groups of ovalbumin (OVA)-induced asthma mice with acute and chronic airway inflammation received ICT. Asthmatic mice received budesonide (BDND) aerosol inhalation as a positive control, while normal control and asthma model mice received the same volume of saline. Following finishing of the study, analyses were conducted on behavioral tests, biochemical indices, and histological structures of lung tissues. RESULTS: Aerosol inhalation of ICT can notably reduce inflammatory cells infiltration around the airways and pulmonary vessels, and suppressed goblet cell hyperplasia in asthmatic mice. Long-term inhalation of ICT can decrease airway collagen deposition and airway smooth muscle hyperplasia, and alleviate airway hyperresponsiveness, mirroring the effects observed with hormone employed in clinical practice. CONCLUSION: Nebulized inhalation of ICT can effectively inhibit airway inflammation in asthmatic mice, improve airway remodeling, and reduce airway hyperresponsiveness, with effects similar to those of hormones. It may serve as a potential candidate used as a hormone replacement asthma treatment.

PDPN positive CAFs contribute to HER2 positive breast cancer resistance to trastuzumab by inhibiting antibody-dependent NK cell-mediated cytotoxicity.

Trastuzumab is a humanized monoclonal antibody, and has been clinical employed to treat human epidermal growth factor receptor 2 (HER2) positive breast cancer. However, drug resistance to trastuzumab remains a challenge due to the generally uncharacterized interactive immune responses within the tumor tissue. In this study, by means of single-cell sequencing, we identified a novel podoplanin-positive (PDPN+) cancer-associated fibroblasts (CAFs) subset, which was enriched in trastuzumab resistant tumor tissues. Furthermore, we found that PDPN+ CAFs promote resistance to trastuzumab in HER2+ breast cancer by secreting immunosuppressive factors indoleamine 2,3-dioxygenase 1 (IDO1) as well as tryptophan 2,3-dioxygenase 2 (TDO2), thereby suppressing antibody-dependent cell-mediated cytotoxicity (ADCC), which was mediated by functional NK cells. A dual inhibitor IDO/TDO-IN-3 simultaneously targeting IDO1 and TDO2 showed a promising effect on reversing PDPN+ CAFs-induced suppression of NK cells mediated ADCC. Collectively, a novel subset of PDPN+ CAFs was identified in this study, which induced trastuzumab resistance in breast cancer of HER2+ status via inhibiting ADCC immune response mediated by NK cells, hinting that PDPN+ CAFs could be a novel target of treatment to increase the sensitivity of HER2+ breast cancer to trastuzumab.

Surface Gradient Desodiation Chemistry in Layered Oxide Cathode Materials.

Sodium-ion batteries (SIBs) as a promising technology for large-scale energy storage have received unprecedented attention. However, the cathodes in SIBs generally suffer from detrimental cathode-electrolyte interfacial side reactions and structural degradation during cycling, which leads to severe capacity fade and voltage decay. Here, we have developed an ultra-stable Na0.72Ni0.20Co0.21Mn0.55Mg0.036O2 (NCM-CS-GMg) cathode material in which a Mg-free core is encapsulated by a shell with gradient distribution of Mg using coprecipitation method with Mg-hysteretic cascade feedstock followed by calcination. From the interior to outer surface of the shell, as the content of electrochemically inactive Mg gradually increases, the Na+ deintercalation amount gradually decreases after charged. Benefiting from this surface gradient desodiation, the surface transition metal (TM) ion migration from TM layers to Na layers is effectively inhibited, thus suppressing the layered-to-rock-salt phase transition and the resultant microcracks. Besides, the less formation of high-valence TM ions on the surface contributes to a stable cathode-electrolyte interface. The as-prepared NCM-CS-GMg exhibits remarkable cycling life over 3000 cycles with a negligible voltage drop (0.127 mV per cycle). Our findings highlight an effective way to developing sustainable cathode materials without compromising on the initial specific capacity for SIBs.

Characteristics of the phonon laser in the active levitated optomechanical system.

Phonon lasers, coherent oscillations of phonons, have gradually become one of the emerging frontiers in the last decades, and have promising applications in quantum sensing, information processing, and precise measurement. Recently, phonon lasers based on dissipative coupling have been realized in an active levitated optomechanical (LOM) system for the first time. Here, we further investigated the characteristics of the phonon laser in the system above regarding the oscillator amplitude and the phonon laser linewidth. We established both the experimental system and a physical model of the phonon laser. On the basis of simulations and experiments, the influences of pumping power, numerical aperture, the microsphere's diameter and refractive index on the performance of the phonon lasers are sufficiently discussed. Our work is of great significance for the high-quality phonon lasers generated by the appropriate parameters, which is the basis for the in-depth research and practical application.

High-sensitivity force sensing using a phonon laser in an active levitated optomechanical system.

Force detection with high sensitivity is of paramount importance in many fields of study, from gravitational wave detection to investigations of surface forces. Here, we propose and demonstrate a force-sensing method based on gain-enhanced nonlinearity in a nonlinear phonon laser. Experimental and simulation results show that the input force leads to the frequency shift of phonon laser, due to nonlinearity. In addition, we further investigate the influences of the pumping power, numerical aperture, and microsphere's refractive index on the performance of this force-sensing system, regarding the sensitivity and the linear response range. Our work paves a new way towards the realization of precise metrology based on the nonlinearity of phonon laser.

Characterization of high-speed electro-optic phase modulators based on heterodyne carrier mapping at a fixed low-frequency.

A self-referenced method based on heterodyne carrier mapping is proposed to characterize the modulation efficiency of high-speed electro-optic phase modulators (EOPMs). The heterodyne carrier mapping replicates the optical carrier after phase modulation to an electrical replica, which enables observing the power variation of the optical carrier at a fixed low-frequency in the electrical domain. The modulation depths and half-wave voltages within the frequency range of up to 40 GHz are determined by measuring the amplitude ratio of the mapped low-frequency component at 80 MHz in the cases of on and off single-tone modulation of the EOPM. The measured results are compared to those obtained with the traditional optical spectrum analysis method and the electrical spectrum sweep method to check the consistency and accuracy. Surpassing the heterodyne spectrum mapping (HSM) scheme, our method only requires a single-tone driving of the EOPM under test and completely avoids the roll-off responsivity of the photodetector through the fixed low-frequency detection.

Lung cancer risk and exposure to air pollution: a multicenter North China case-control study involving 14604 subjects.

BACKGROUND: For North Chinese lung cancer patients, there is limited study on the distribution of air pollution and smoking related features based on analyses of large-scale, high-quality population datasets. The aim of the study was to fully analyze risk factors for 14604 Subjects. METHODS: Participants and controls were recruited in 11 cities of North China. Participants' basic information (sex, age, marital status, occupation, height, and weight), blood type, smoking history, alcohol consumption, history of lung-related diseases and family history of cancer were collected. PM2.5 concentration data for each year in each city of the study area from 2005 to 2018 were extracted based on geocoding of each person's residential address at the time of diagnosis. Demographic variables and risk factors were compared between cases and matched controls using a univariate conditional logistic regression model. Multivariate conditional logistic regression models were applied to estimate the odds ratio (OR) and 95% confidence interval (CI) for risk factors in univariate analysis. The nomogram model and the calibration curve were developed to predict lung cancer probability for the probability of lung cancer. RESULTS: There was a total of 14604 subjects, comprising 7124 lung cancer cases and 7480 healthy controls included in the study. Marital status of unmarried persons, people with a history of lung-related disease, corporate personnel and production /service personnel were protective factors for lung cancer. People younger than 50 years old, people who were smoking and quit smoking, people who had been drinking consistently, people with family history of cancer and PM2.5 exposure were proven to be a risk factor for lung cancer. The risk of lung cancer varied with sex, smoking status and air pollution. Consistent alcohol consumption, persistent smoking and smoking quit were risk factors for lung cancer in men. By smoking status, male was risk factor for lung cancer in never smokers. Consistent alcohol consumption added risk for lung cancer in never smokers. The combined effects of PM2.5 pollution exposure and ever smoking aggravated the incidence of lung cancer. According to air pollution, lung cancer risk factors are completely different in lightly and heavily polluted areas. In lightly polluted areas, a history of lung-related disease was a risk factor for lung cancer. In heavily polluted areas, male, consistent alcohol consumption, a family history of cancer, ever smokers and smoking quit were all risk factors for lung cancer. A nomogram was plotted and the results showed that PM2.5 was the main factor affecting the occurrence of lung cancer. CONCLUSIONS: The large-scale accurate analysis of multiple risk factors in different air quality environments and various populations, provide clear directions and guidance for lung cancer prevention and precise treatment.

MC3/SAINT-O-Somes, a novel liposomal delivery system for efficient and safe delivery of siRNA into endothelial cells.

Increased understanding of chronic inflammatory diseases and the role of endothelial cell (EC) activation herein, have urged interest in sophisticated strategies to therapeutically intervene in activated EC to treat these diseases. Liposome-mediated delivery of therapeutic siRNA in inflammation-activated EC is such a strategy. In this study, we describe the design and characterisation of two liposomal siRNA delivery systems formulated with the cationic MC3 lipid or MC3/SAINT mixed lipids, referred to as MC3-O-Somes (MOS) and MC3/SAINT-O-Somes (MSS). The two formulations showed comparable physicochemical properties, except for better siRNA encapsulation efficiency in the MSS formulation. Antibody-mediated VCAM-1 targeting (AbVCAM-1) increased the association of the targeted MOS and MSS with activated EC, although the targeted MOS showed a significantly higher VCAM-1 specific association than the targeted MSS. AbVCAM-1 MSS containing RelA siRNA achieved significant downregulation of RelA expression, while AbVCAM-1 MOS containing RelA siRNA did not downregulate RelA expression in activated EC. Additionally, AbVCAM-1 MSS containing RelA siRNA showed low cytotoxicity in EC and at the same time prohibited endothelial inflammatory activation by reducing expression of cell adhesion molecules. The AbVCAM-1 MSS formulation is a novel siRNA delivery system based on a combination of the cationic lipids MC3 and SAINT, that shows good physicochemical characteristics, enhanced endothelial cell association, improved transfection activity, low toxicity and significant anti-inflammatory effect, thereby complying with the requirements for future in vivo investigations.

High-frequency characterization of electro-optic modulation chips based on photonic down-conversion sampling and microwave fixture de-embedding.

A self-reference and on-chip method for extracting the intrinsic frequency responses including modulation index and half-wave voltage of electro-optic modulator (EOM) chips is proposed based on photonic down-conversion sampling and microwave fixture de-embedding. The photonic down-conversion sampling is firstly employed to extract the combined response of the source network SxN, the adapter network SAN and the EOM chip. Then the Open-Short-Load (OSL) calibration is exploited to realize the on-chip microwave de-embedding of SxN and SAN in terms of the transmission attenuation and the impedance mismatch. Finally, the power leveling technique is used to track the incident microwave power to obtain the intrinsic half-wave voltage of the EOM chip. Our method features self-reference and on-chip capability, which is applicable for the EOM chips even without a good impedance match, and is free of any extra optical/electrical (O/E) transducer standard, which will be helpful to chip evaluation and packaging optimization.

Relative frequency response measurement of Mach-Zehnder modulators utilizing dual-carrier modulation and low-frequency detection.

A self-calibrated approach is proposed to measure the relative frequency response of Mach-Zehnder modulators (MZMs) based on dual-carrier modulation and low-frequency detection. In this scheme, a dual-carrier is generated by combining a continuous-wave light from a distributed feedback laser diode with its frequency-shifted replica. Through modulating the dual-carrier by a frequency-scanned single-tone microwave signal via the MZM under test biased at its minimum transmission point, a fixed low-frequency heterodyne signal carrying the electro-optic modulation response information is generated after photodetection, from which the relative frequency response of the MZM can be obtained. In the experiment, the relative frequency response of a commercial MZM is measured by using the proposed method, where the result fits in with those obtained by using the conventional optical spectrum analysis method and the microwave network analysis method. The proposed method features self-calibration, high frequency resolution, low-frequency detection, and usage of only a single frequency-scanned microwave source, which is favorable for characterizing the microwave performance of MZMs in backbone optical communication and microwave photonic systems.

Self-referenced electro-optic response measurement of dual-parallel Mach-Zehnder modulators employing single-tone level control and low-frequency bias swing.

A self-referenced method is proposed to characterize the electro-optic frequency response of dual-parallel Mach-Zehnder modulators (DPMZMs) based on single-tone level control and low-frequency bias swing. The single-tone driving signal and the low-frequency bias signal of the DPMZM mix with each other after photodetection, and a low-frequency beat note is generated in the electrical domain. The functional relationship between the desired low-frequency amplitude and the single-tone driving level is investigated and established, from which the modulation depth and half-wave voltage are extracted with the help of regression analysis. We experimentally demonstrate the feasibility of the proposed method and compare it with the conventional ones to check the consistency. The self-referenced method features single-tone modulation and low-frequency detection for measuring high-speed DPMZMs, which avoids the use of a broadband photodetector (PD) and the influence of the uneven response of the PD.

Self-reference frequency response characterization of photodiode chips based on photonic sampling and microwave de-embedding.

In this work, we propose and demonstrate a self-reference on-chip testing method to obtain the frequency response characteristics of photodiode chips based on photonic sampling and microwave de-embedding. The half-frequency photonic sampling enables self-reference extraction of the combined response of the photodiode chip, the adapter network and the receiver network. The microwave de-embedding under short-open-load-device (SOLD) termination is used to realize on-chip de-embedding of the adapter network and the receiver network in terms of the transmission loss and the impedance mismatch. The proposed on-chip testing method is free of any extra electro-optical transducer standard, which is favorable for performance monitoring in chip evaluation.

Synthesis and anti-inflammatory activity of paeonol derivatives with etherized aryl urea by regulating TLR4/MyD88 signaling pathway in RAW264.7 cell.

Thirty-three novel paeonol etherized aryl urea derivatives (PEUs) were synthesized via a bromination-Williamson Ether Synthesis-deprotection-nucleophilic addition reaction sequence. The structures of PEUs were characterized by LC-MS, HRMS, 1H NMR and 13C NMR spectra. The levels of nitric oxide (NO), tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1ß) in lipopolysaccharide (LPS)-induced RAW264.7 macrophages were initially employed to evaluate the anti-inflammatory effects of all compounds. Remarkably, b16 exhibited a good anti-inflammatory activity at 2.5 µm which is the same as the potency of paeonol at 20 µm. The results of mechanism research displayed that the anti-inflammatory effect of b16 was ascribed to the inhibition of the TLR4/MyD88 signaling pathway and inflammatory factors. Additionally, b16 distinctly reduced the generation of free radicals in macrophages and strikingly increased the mitochondrial membrane potential. According to the structure-activity relationships (SAR) of PEUs, the incorporation of halogens on the benzene ring and the hydrogen of phenol hydroxyl substituted by aryl urea, were beneficial to enhance the anti-inflammatory activities. Molecular docking results illustrated that the binding ability of b16 to TLR4 was stronger than that of paeonol. In summary, the novel aryl urea-derivied paeonol b16 could be a new promising candidate for the treatment of inflammation-related diseases.

Using Quasispecies Patterns of Hepatitis B Virus to Predict Hepatocellular Carcinoma With Deep Sequencing and Machine Learning.

BACKGROUND: Hepatitis B virus (HBV) infection is one of the main leading causes of hepatocellular carcinoma (HCC) worldwide. However, it remains uncertain how the reverse-transcriptase (rt) gene contributes to HCC progression. METHODS: We enrolled a total of 307 patients with chronic hepatitis B (CHB) and 237 with HBV-related HCC from 13 medical centers. Sequence features comprised multidimensional attributes of rt nucleic acid and rt/s amino acid sequences. Machine-learning models were used to establish HCC predictive algorithms. Model performances were tested in the training and independent validation cohorts using receiver operating characteristic curves and calibration plots. RESULTS: A random forest (RF) model based on combined metrics (10 features) demonstrated the best predictive performances in both cross and independent validation (AUC, 0.96; accuracy, 0.90), irrespective of HBV genotypes and sequencing depth. Moreover, HCC risk scores for individuals obtained from the RF model (AUC, 0.966; 95% confidence interval, .922-.989) outperformed α-fetoprotein (0.713; .632-.784) in distinguishing between patients with HCC and those with CHB. CONCLUSIONS: Our study provides evidence for the first time that HBV rt sequences contain vital HBV quasispecies features in predicting HCC. Integrating deep sequencing with feature extraction and machine-learning models benefits the longitudinal surveillance of CHB and HCC risk assessment.

Frequency response measurement of high-speed photodiodes based on a photonic sampling of an envelope-modulated microwave subcarrier.

An approach to measuring the frequency response of high-speed photodiodes (PDs) is proposed and experimentally demonstrated based on employing an ultrashort optical pulse train to sample an envelope-modulated microwave subcarrier. Through up-and-down conversion sampling, a varying frequency component and a fixed low frequency component can be obtained, where the varying frequency component probes the ultra-wideband response information of PD. Through measuring the relative amplitude between the two frequency components, the frequency response of the PD at the any frequency within ultra-wideband frequency range can be calculated by taking the response at the fixed low frequency component as a reference. Thereinto, the frequency response of the electro-optic modulator is cancelled out, and the uneven comb intensity introduced by the ultrashort optical pulse train can be corrected by choosing the specific frequency of the microwave subcarrier. In the proof-of-concept experiment, the self-calibrated frequency response measurement of a commercial PD is demonstrated by employing an optical pulse train with a repetition rate of 9.954 GHz and an electro-optic frequency sweeping up to 4.977 GHz. The frequency measurement range is achieved up to 49.77 GHz, and the frequency resolution reaches 300 kHz in the rough measurement and 10 Hz level in the fine measurement. The consistency between the proposed method and conventional methods proves the ultra-wideband and hyperfine frequency response measurement of PDs.

Simultaneous frequency response measurement of electro-absorption modulation transceivers based on a self-referenced pilot operation.

An electro-optic method based on a self-referenced pilot operation is proposed for simultaneously characterizing electro-absorption modulation optoelectronic transceivers with a shared setup. Through inserting and extracting the self-referenced pilot, the frequency responses of electro-absorption modulated lasers (EMLs) and photodetectors (PDs) are independently obtained in a single measurement, and any extra optical-to-electrical or electrical-to-optical calibration is avoided. Specifically, the relative frequency response of the EML at fm is determined through the extracted difference-frequency pilot at fp (close to DC), realizing the low-frequency analysis for an EML. The relative frequency response of PD at 2fm+fp is obtained from the amplitude ratio of the extracted sum- and difference-frequency pilots at 2fm+fp and fp under the microwave driving signal at fm, verifying the doubled measuring frequency range. In the proof-of-concept demonstration, the frequency response of an electro-absorption modulation transceiver is measured up to 40 GHz. Thereinto, the frequency response of the EML is obtained by detecting the fixed low-frequency pilot of 10 kHz, and the frequency response of the PD is extracted with frequency-swept modulation to 20 GHz. The experiment results are compared with those obtained with the electro-optic frequency sweeping method to check for accuracy.