Hyperbaric Oxygen Improves Long-Term Learning and Memory Impairment by Attenuating Neuronal Apoptosis in aMCI Rats.

Background: With the aging of the population and the increasing incidence of neurological diseases, amnestic mild cognitive impairment (aMCI) has attracted attention. Hyperbaric oxygen (HBO) has gradually shown the potential in the treatment of aMCI as an emerging treatment method in recent times. This study is to observe the effect of HBO on the long-term learning memory of aMCI rats, and investigate the associated mechanisms. Methods: Seventy-two male rats (4-month-old) were randomly divided into control (CON) group, aMCI group, HBO group, 24 rats in each group. Each group was randomly divided into CON1, CON7, CON28; aMCI1, aMCI7, aMCI28; HBO1, HBO7, HBO28, 8 rats in each group. The aMCI model rats were established in aMCI and HBO groups. HBO group was treated with HBO for 7 days. The ethological and cytopathology which include Morris water maze (MWM) test, HE staining, TUNEL staining and the expression of Fas/FasL on neuron membrane were conducted to evaluate the effects of HBO on day 1, day 7 and day 28 after HBO treatment. Results: MWM test showed that the spatial learning and memory ability of the rats decreased in aMCI group, and recovered in HBO group; Compared with aMCI group, the pathological damage of hippocampal nerve cells was alleviated, the number of apoptotic cells was significantly reduced (P < 0.05), and the expression of Fas/FasL on the surface of nerve cell membrane was significantly weakened in HBO group (P < 0.05). There were no significant changes in the spatial learning and memory ability, pathological damage of hippocampal neurons, the number of apoptotic cells, and the changes of Fas/FasL on the surface of hippocampal neurons in HBO1, HBO7, and HBO28 groups (P > 0.05). However, in aMCI1, aMCI7, and aMCI28 groups gradually aggravated (P < 0.05). Conclusion: 1. HBO can improve the long-term learning and memory impairment by attenuating neuronal apoptosis in aMCI rats. 2. Fas/FasL mediated cell receptor death pathway is involved in the apoptosis of hippocampal neurons.

Water-Immersible MEMS Mirror with a Large Optical Aperture.

This paper presents a two-axis AlScN-based water-immersible MEMS mirror fabricated in an 8-inch MEMS process. Compared with other studies, this device has a larger optical aperture 10 mm in diameter. The resonant frequencies of the device are 1011 Hz in air and 342 Hz in water. The scanning angle reaches ±5° and ±2° at resonant frequencies in air and water, respectively. The cavitation phenomenon is observed when the device is operating in water, which leads the device to electrical failure. To address this issue, a device with reduced resonant frequencies-246 Hz and 152 Hz in air and water-is characterized, through which the bubbles can be effectively prohibited. This MEMS mirror could potentially be used in ultrasound and photoacoustic microscopy applications.

Association between NTCP hepatic expression and inflammation/fibrosis as well as gender-specific differences in chronic HBV-infected patients.

To investigate the relationship between the expression of hepatitis B virus (HBV) functional receptor sodium taurocholate cotransporting polypeptide (NTCP) with disease progression and gender-specific differences in chronic HBV-infected patients. Liver samples were collected from chronic HBV-infected patients who underwent percutaneous liver biopsy or liver surgery. HBV DNA levels and the mRNA and protein expression levels of NTCP in liver tissues were determined. The relationship between NTCP expression and HBV DNA levels, inflammatory activity, fibrosis, and gender-specific differences were analyzed. A total of 94 chronic HBV-infected patients were included. Compared with patients with a METAVIR score of A0-1 or F0-1, patients with score of A2 or F2/F3 had a relatively higher level of NTCP expression. NTCP levels were positively correlated with HBV DNA levels. The inflammatory activity scores and fibrosis scores of women <50 years were significantly lower than those of women ≥50 years and age-matched males. In patients with score A0-2 or F0-3, women <50 years have lower NTCP expression level compared to women ≥50 years and age-matched males. NTCP can promote the disease progression by affecting the viral load of HBV. The NTCP expression difference may be why male and postmenopausal women are more prone to disease progression than reproductive women.

Comprehensive comparative analysis of the prognostic impact of systemic inflammation biomarkers for patients underwent cardiac surgery.

Background: Inflammation plays an integral role in the development of cardiovascular disease, and few studies have identified different biomarkers to predict the prognosis of cardiac surgery. But there is a lack of reliable and valid evidence to determine the optimal systemic inflammatory biomarkers to predict prognosis. Methods: From December 2015 and March 2021, we collected 10 systemic inflammation biomarkers among 820 patients who underwent cardiac surgery. Time-dependent receiver operating characteristic curves (ROC) curve at different time points and C-index was compared at different time points. Kaplan-Meier method was performed to analyze overall survival (OS). Cox proportional hazard regression analyses were used to assess independent risk factors for OS. A random internal validation was conducted to confirm the effectiveness of the biomarkers. Results: The area under the ROC of lymphocyte-to-C-reactive protein ratio (LCR) was 0.655, 0.620 and 0.613 at 1-, 2- and 3-year respectively, and C-index of LCR for OS after cardiac surgery was 0.611, suggesting that LCR may serve as a favorable indicator for predicting the prognosis of cardiac surgery. Patients with low LCR had a higher risk of postoperative complications. Besides, Cox proportional hazard regression analyses indicated that LCR was considered as an independent risk factor of OS after cardiac surgery. Conclusion: LCR shows promise as a noteworthy representative among the systemic inflammation biomarkers in predicting the prognosis of cardiac surgery. Screening for low LCR levels may help surgeons identify high-risk patients and guide perioperative management strategies.

Metabolic disorders induced by PNPLA3 and TM6SF2 gene variants affect chronic kidney disease in patients infected with non-genotype 3 hepatitis C virus.

BACKGROUND: Patients with chronic hepatitis C virus (HCV) infections differ in their risk for metabolic disorders and chronic kidney disease (CKD). The aim of this study was to investigate the effect of metabolic disorders induced by genetic factors on CKD in HCV-infected patients. METHODS: Patients with chronic non-genotype 3 HCV infection with or without CKD were examined. PNPLA3 and TM6SF2 variants were determined using high-throughput sequencing. The relationships of variants and different combinations with metabolic disorders were analyzed in CKD patients. Univariate and multivariate analyses were used to identify factors associated with CKD. RESULTS: There were 1022 patients with chronic HCV infection, 226 with CKD and 796 without CKD. The CKD group had more severe metabolic disorders, and also had higher prevalences of liver steatosis, the PNPLA3 rs738409 non-CC genotype, and the TM6SF2 rs58542926 CC genotype (all P < 0.05). Relative to patients with the PNPLA3 rs738409 CC genotype, patients with the non-CC genotype had a significantly decreased eGFR and a greater prevalence of advanced CKD (CKD G4-5). Patients with the TM6SF2 rs58542926 CC genotype had a lower eGFR and a higher prevalence of CKD G4-5 than those with the non-CC genotype. Multivariable analysis indicated that multiple metabolic abnormalities, including liver steatosis and the PNPLA3 rs738409 C > G variant, increased the risk of CKD, but the TM6SF2 rs58542926 C > T variant decreased the risk of CKD. CONCLUSION: Specific PNPLA3 rs738409 and TM6SF2 rs58542926 variants are independent risk factors for CKD in patients with chronic HCV infections and are associated with the severity of renal injury.

Resolution adjustable Lissajous scanning with piezoelectric MEMS mirrors.

We previously designed a dual-axis piezoelectric MEMS mirror with a low crosstalk gimbal structure, which is utilized as the key device for further research for laser beam scanning. This paper mainly focuses on studying the Lissajous scanning resolution of this MEMS mirror with frequency ratio and phase modulation. For accurately evaluating the scanning resolution, the center angular resolution of Lissajous scanning is redefined by theoretical calculation and verified with experimental measurement. Meanwhile, the scanning nonlinearity of MEMS mirror is studied carefully. Finally, the MEMS mirror works at the state of pseudo-resonance, and the center angular resolution better than 0.16° (H) × 0.03° (V) is achieved at a scanning Field of view (FoV) of 35.0° (H) × 16.5° (V). Moreover, a feasible route of resolution adjustable Lissajous scanning is provided by optimization of frequency ratio and phase modulation, which is helpful for high definition and high frame rate (HDHF) laser scanning imaging with the dual-axis mirror.

The Antibacterial Activity Mode of Action of Plantaricin YKX against Staphylococcus aureus.

We aimed to evaluate the inhibitory effect and mechanism of plantaricin YKX on S. aureus. The mode of action of plantaricin YKX against the cells of S. aureus indicated that plantaricin YKX was able to cause the leakage of cellular content and damage the structure of the cell membranes. Additionally, plantaricin YKX was also able to inhibit the formation of S. aureus biofilms. As the concentration of plantaricin YKX reached 3/4 MIC, the percentage of biofilm formation inhibition was over 50%. Fluorescent dye labeling combined with fluorescence microscopy confirmed the results. Finally, the effect of plantaricin YKX on the AI-2/LuxS QS system was investigated. Molecular docking predicted that the binding energy of AI-2 and plantaricin YKX was -4.7 kcal/mol and the binding energy of bacteriocin and luxS protein was -183.701 kcal/mol. The expression of the luxS gene increased significantly after being cocultured with plantaricin YKX, suggesting that plantaricin YKX can affect the QS system of S. aureus.

Signal transducer and activator of transcription 3 cooperates with androgen receptor/cell cycle-related kinase signalling pathway in the progression of hepatitis B virus infection and gender differences.

The study aimed to investigate the role of androgen receptor (AR)/cell cycle-related kinase (CCRK) signalling pathway in chronic hepatitis B virus (HBV) infection and gender differences, and the contribution of AR regulatory factor signal transducer and activator of transcription 3 (STAT3) in it. AR, CCRK, and phosphorylated STAT3 expressions in liver tissues of chronic HBV-infected patients and non-HBV controls were determined by western blot and compared between genders. The relationships of expression levels with serum HBV DNA levels, liver inflammation activity, and fibrosis score were analysed in chronic HBV-infected patients. The relationships between expression levels of three proteins were also analysed. HBV-infected patients had significantly higher expression levels of AR, CCRK, and p-STAT3Tyr705 compared with controls (p < .01). The expression levels of AR, CCRK, and p-STAT3Tyr705 in chronic HBV-infected patients with severe inflammation were significantly higher than those with mild inflammation (p < .05). Expression levels in patients with heavier fibrosis (stage F4) were higher than in those with less fibrosis (stages F0-3) (p < .01). No gender differences were observed in AR, CCRK, and p-STAT3Tyr705 levels in non-HBV controls; higher levels were observed in HBV-infected males than in HBV-infected females (p < .05). AR, CCRK, and p-STAT3Tyr705 levels in liver tissues positively correlated with each other (p < .0001) and with serum HBV DNA levels (p < .0001). In conclusion, in this study, we first found concordant over-expression of AR, CCRK, and STAT3 in liver tissues of chronic HBV-infected patients who have not yet developed HCC, significantly correlated with the severity of the disease and showed gender differences. STAT3 may be a potential therapeutic co-target for chronic HBV infection.

Facile and Green Synthesis of Highly Fluorescent Carbon Quantum Dots from Water Hyacinth for the Detection of Ferric Iron and Cellular Imaging.

Natural biomass is used for facile synthesis of carbon quantum dots (CQDs) with high fluorescence, owing to its abundance, low cost, and eco-friendliness. In this study, a bottom-up hydrothermal method was used to prepare CQDs from water hyacinth (wh) at a constant temperature of 180 °C for 12 h. The synthesized wh-CQDs had uniform size, amorphous graphite structure, high water solubility (containing multiple hydroxyl and carboxyl groups on the surface), excitation light-dependent characteristics, and high photostability. The results showed that the aqueous solution of CQDs could detect Fe3+ rapidly, sensitively, and highly selectively with a detection limit of 0.084 µM in the linear range of 0-330 µM, which is much lower than the detection limit of 0.77 µM specified by the World Health Organization. More importantly, because the wh-CQDs were synthesized without any additives, they exhibited low toxicity to Klebsiella sp. cells even at high concentrations. Moreover, wh-CQDs emitted bright blue fluorescence in Klebsiella sp. cells, indicating its strong penetrating ability. Correspondingly, the fluorescent cell sorting results also revealed that the proportion of cell internalization reached 41.78%. In this study, wh-CQDs derived from natural biomass were used as high-performance fluorescent probes for Fe3+ detection and Klebsiella sp. imaging. This study is expected to have great significance for the application of biomass carbon spots in the field of cellular imaging and biology.

Purification and Characterization of Plantaricin YKX and Assessment of Its Inhibitory Activity Against Alicyclobacillus spp.

Consumers prefer natural over synthetic chemical preservatives on a food label. Therefore, it is crucial to ensure the safety and efficacy of such natural preservatives. The emergence of heat-resistant spore-forming Alicyclobacillus spp. has been associated with spoilage problems in the fruit juice industry. Herein, a bacteriocin-producing stain YKX was isolated from the traditional pickles in Hanzhong City, China, and it was identified as Lactobacillus plantarum by morphological, biochemical, physiological, and genotypic features. A stable bacteriocin, plantaricin YKX, was isolated, purified, and tested for its efficacy against Alicyclobacillus acidoterrestris. Plantaricin YKX is a 14-amino acid peptide (Lys-Tyr-Gly-Asn-Gly-Leu-Ser-Arg-Ile-Phe-Ser-Ala-Leu-Lys). Its minimal inhibitory concentrations (MICs) against the tested bacterial and fungal strains were ranged from 16 to 64 µg/mL. It is thermostable and active at pH 3-8. The flow cytometry data and microscopic observations suggested that plantaricin YKX can augment cell membrane permeability, induce potassium ion leakage and pore formation, and disrupt cell membranes. It also affects spore germination and guaiacol production of A. acidoterrestris, probably due to upregulation of the luxS gene linked to quorum sensing.

Oxygen doping in antimony sulfide nanosheets to facilitate catalytic conversion of polysulfides for lithium-sulfur batteries.

A high-performance catalyst, O-doped Sb2S3 nanosheets (SS-O NSs), is synthesized and introduced into lithium-sulfur batteries. Owing to their good conductivity, strong adsorbability/catalytic effect to polysulfides and fast Li+ diffusion, the SS-O NSs-modified cathodes can effectively mitigate the shuttle effect, thus achieving outstanding electrochemical performance.

Serum Vitamin D Levels and Risk of Liver Cancer: A Systematic Review and Dose-Response Meta-Analysis of Cohort Studies.

Data regarding the relationship between serum vitamin D levels and the risk of liver cancer are conflicting. Therefore, we performed a systematic review and dose-response meta-analysis of all available data of cohort studies on the association of 25-OH-vitamin-D levels with the risk of hepatocellular carcinoma. We conducted a systematic search in PubMed-MEDLINE, Scopus, Cochrane and Web of Science databases for prospective observational studies conducted on the general population from inception to May 2019. Six studies provided data from 6357 participants. According to the pooled HR, the subjects with the highest serum concentrations of vitamin D had a 47% lower risk of liver cancer vs. the subjects with the lowest serum concentrations of vitamin D (pooled HR: 0.53, 95% CI: 0.41-0.68; P < 0.001). There was no significant heterogeneity among the studies (P = 0.431, I2 = 0.0). The pooled HR from the random-effects dose-response model indicated an indirect significant linear association between vitamin D and the risk of liver cancer (coef = -0.017, P < 0.001). However, there was no significant nonlinear dose-response association between serum vitamin D and the risk of liver cancer (coef = -0.0001, P = 0.342). The evidence from this meta-analysis suggests that there may be an inverse relationship between serum vitamin D levels and the risk of liver cancer.

Effect of baseline resistance-associated substitutions on the efficiency of glecaprevir/pibrentasvir in chronic hepatitis C subjects: A meta-analysis.

The effect of baseline resistance-associated substitutions on the sustained virologic response at 12 weeks in chronic hepatitis C subjects has drawn considerable attention. However, it has been reported that the relationship between such substitutions and sustained virologic response at 12 weeks in chronic hepatitis C subjects is variable in different treatments. This meta-analysis was performed to evaluate this relationship in subjects treated with glecaprevir/pibrentasvir. A systematic literature search up to May 2020 was done, and 17 studies were identified with 6501 chronic hepatitis C subjects. They were reporting relationships between baseline resistance-associated substitutions and sustained virologic response at 12 weeks in chronic hepatitis C subjects treated with glecaprevir/pibrentasvir. The odds ratio (OR) with 95% confidence intervals (CIs) was calculated to evaluate the prognostic role of baseline resistance-associated substitutions on the sustained virologic response at 12 weeks in chronic hepatitis C subjects treated with glecaprevir/pibrentasvir using the dichotomous method with a random or fixed-effect model. Lower sustained virologic response at 12 weeks post-treatment in chronic hepatitis C subjects was significantly related to baseline resistance-associated substitutions in overall genotypes (OR, 0.03; 95% CI, 0.15-0.61, P < .001), baseline NS5a resistance-associated substitutions in genotype-1 (OR, 0.16; 95% CI, 0.04-0.57, P = .005), baseline resistance-associated substitutions in genotype-3 (OR, 0.14; 95% CI, 0.05-0.38, P < .001), and baseline NS5a resistance-associated substitutions in genotype-3 (OR, 0.21; 95% CI, 0.09-0.49, P < .001). Sustained virologic response at 12 weeks in chronic hepatitis C subjects was not significantly related to the baseline NS5a resistance-associated substitutions (OR, 0.61; 95% CI, 0.17-2.22, P = .45), and baseline resistance-associated substitutions in genotype-1 (OR, 0.35; 95% CI, 0.12-1.088, P = .07). In conclusion, the impact of baseline resistance-associated substitutions on the sustained virologic response at 12 weeks in chronic hepatitis C subjects treated with glecaprevir/pibrentasvir may have a great prognostic effect, especially in genotype-3 as a tool to improve treatment prediction. Chronic hepatitis C subjects with baseline resistance-associated substitutions may have an independent risk relationship with poor treatment outcomes. This relationship forces us to recommend testing prior to treatment selection to avoid any possible treatment failure.

Dual-Regulation Strategy to Improve Anchoring and Conversion of Polysulfides in Lithium-Sulfur Batteries.

The sluggish reaction kinetics at the cathode/electrolyte interface of lithium-sulfur (Li-S) batteries limits their commercialization. Herein, we show that a dual-regulation system of iron phthalocyanine (FePc) and octafluoronaphthalene (OFN) decorated on graphene (Gh), denoted as Gh/FePc+OFN, accelerates the interfacial reaction kinetics of lithium polysulfides (LiPSs). Multiple in situ spectroscopy techniques and ex situ X-ray photoelectron spectroscopy combined with density functional theory calculations demonstrate that FePc acts as an efficient anchor and scissor for the LiPSs through Fe···S coordination, mainly facilitating their liquid-liquid transformation, whereas OFN enables Li-bond interaction with the LiPSs, accelerating the kinetics of the liquid-solid nucleation and growth of Li2S. This dual-regulation system promotes the smooth conversion reaction of sulfur, thereby improving the battery performance. A Gh/FePc+OFN-based Li-S cathode delivered an ultrahigh initial capacity of 1604 mAh g-1 at 0.2 C, with an ultralow capacity decay rate of 0.055% per cycle at 1 C over 1000 cycles.

Resonant fiber optic gyroscope with three-frequency differential detection by sideband locking.

A new scheme of three-frequency differential detection with a sideband locking technique is firstly proposed to suppress backscattering noise for improving the accuracy of resonator fiber optic gyroscope (RFOG). In the system we proposed, one light path is divided into three paths and sinusoidal wave modulations of different frequencies are respectively applied to generate the sideband. The first-order sidebands of the three channels of light in the cavity are locked to the adjacent three resonance peaks by sideband locking technique. The carrier and the remaining sidebands of the three channels of light are moved to a position away from the resonance peak, thereby achieving the purpose of being suppressed by the cavity itself. As a result, the frequency difference between the CW light and the other two CCW lights reaches one free spectral range (FSR), eliminating the expected backscattering noise. The experimental results demonstrate that the RFOG has a bias stability 0.9°/h based on the Allan deviation, and the corresponding angular random walk (ARW) 0.016°/√h, which validate that our scheme can effectively suppress backscattering noise to promote performance of RFOG in practical applications.

Peg-interferon and nucleos(t)ide analogue combination at inception of antiviral therapy improves both anti-HBV efficacy and long-term survival among HBV DNA-positive hepatocellular carcinoma patients after hepatectomy/ablation.

Antiviral therapy has been shown to improve the prognosis of hepatitis B virus (HBV) DNA-positive hepatocellular carcinoma (HCC) after radical treatment, but antiviral treatments require further optimization. This study aimed to evaluate the efficacies of different antiviral strategies with HCC patients after hepatectomy/ablation. This prospective, randomized, controlled and multi-centre trial enrolled HBV DNA-positive primary HCC patients after hepatectomy/ablation between January 2007 and January 2009. Patients were divided into four groups: early combination (entecavir plus Peg-interferon [IFN]α-2a co-administration during year 1); late combination (addition of Peg-IFNα-2a for 48 weeks after 1 year of entecavir); nucleos(t)ide analogue[NA] monotherapy; and non-antiviral treatment. Primary endpoints included recurrence-free survival and overall survival. A total of 447 patients were enrolled. The 2-year and 8-year recurrence-free survival and 8-year overall survival rates were significantly higher in the early combination group than in the other two antiviral groups (P < .05). After 48-week treatment, more patients achieved an HBsAg reduction >1500 IU/mL and the mean HBsAg level was significantly lower in the early combination group compared with the late combination and NA monotherapy groups (P < .05). Multivariate analysis showed that early combination therapy and a reduction in HBsAg by >1500 IU/mL after 48 weeks of therapy correlated with reduced mortality and disease recurrence. Early introduction of combination antiviral treatment may represent a more effective therapeutic strategy for patients with HBV DNA-positive HCC after hepatectomy/ablation. A reduction in HBsAg by >1500 IU/mL after 48-week treatment is associated with reduced mortality and disease recurrence of HBV DNA-positive HCC patients after hepatectomy/ablation.

The influence of interleukin 28B polymorphisms on the risk of hepatocellular carcinoma among patients with HBV or HCV infection: An updated meta-analysis.

Single nucleotide polymorphisms (SNPs) of the interleukin 28B (IL28B) gene has proven to be associated with the clinical outcome of patients with chronic hepatitis virus B or C (HBV or HCV) infections. However, whether IL28B SNPs have an influence on the risk of hepatocellular carcinoma (HCC) among patients with HBV or HCV infection remains controversial. Therefore, this study aims to determine the association between IL28B polymorphisms and the risk of HCC in individuals with HBV or HCV infection.PubMed, EMBASE, and Chinese National Knowledge Infrastructure (CNKI) databases were used to identify studies meeting the selection requirements using the terms "interleukin 28B", "IFN-lambda-3", "IFNL3", "single nucleotide polymorphisms", "SNPs", "hepatocellular carcinoma", "HCC", "liver cancer".A total of 24 eligible original studies (1 cohort study and 23 case-control studies) involved 20238 individuals (HCC group = 8725 vs control group = 11,513) were included. Both IL28B rs12979860 CC and rs8099917 TT genotypes were significantly associated with a decreased risk of HCC among patients with HBV or HCV infection (OR = 0.71, 95% CI = 0.57-0.88; OR = 0.82, 95% CI = 0.72-0.94, respectively). Egger test and Begg test revealed no' publication bias (P > .05). Sensitivity analyses suggested the robustness of the results in this meta-analysis.Both IL28B rs12979860 CC and rs8099917 TT genotypes are protective factors for the development of HCC among patients with HBV or HCV infection. Future prospective studies examining the impact of IL28B polymorphisms on the risk of HCC and investigating the underlying mechanism for the protective role of IL28B polymorphisms in HCC development are warranted.

Titanium silicalite as a radical-redox mediator for high-energy-density lithium-sulfur batteries.

Lithium-sulfur (Li-S) batteries are receiving intense interest owing to their high energy densities, cost effectiveness, and the natural abundance of sulfur. However, practical applications are still limited by rapid capacity decay caused by multielectron redox reactions and complex phase transformations. Here, we include commercially available titanium silicalite-1 (TS-1) in carbon/sulfur cathodes, to introduce strong chemical interactions between the lithium polysulfides (LiPS) and TS-1 in a working Li-S battery. In situ UV-visible spectroscopy together with other experimental results confirm that incorporation of TS-1 mediators enables direct conversion between S82- and S3*- radicals during the discharge process, which effectively promotes the kinetic behaviors of soluble LiPS and regulates uniform nucleation and growth of solid sulfide precipitates. These features give our TS-1 engineered sulfur cathode an ultrahigh initial capacity of 1459 mA h g-1 at 0.1C. Moreover, the system has an impressively high areal capacity (3.84 mA h cm-2) and long cycling stability with a high sulfur loading of 4.9 mg cm-2. This novel and low-cost fabrication procedure is readily scalable and provides a promising avenue for potential industrial applications.

Design of low-crosstalk polarizing resonator and homologous multi-frequency differential detection for hollow-core photonic-crystal fiber optic gyro.

In order to suppress the undesired polarization in the hollow-core photonic-crystal fiber (HCPCF) resonator and reduce the loss of the resonator, we realize a low-crosstalk polarizing resonator with the polarization-correlated phase modulation technique (PCPM). In addition, we put forward a homologous multi-frequency differential detection scheme, with which the backscattering noise and the backreflection noise of the gyro can be well suppressed. Finally, we realize a hollow-core photonic-crystal fiber optic gyro based on the low-crosstalk polarizing resonator and the homologous multi-frequency differential detection. With this novel gyro system, a bias stability of 1.23°/h is successfully demonstrated.

Free spectral range measurement using homologous heterodyne optical phase-locked loop based on acousto-optic modulation.

We demonstrate a homologous heterodyne optical phase-locked loop for free spectral range measurement of a fiber ring resonator. In this loop, the frequency noise within the 10 Hz bandwidth is reduced by more than 40 dB from 147.350 to 0.014 Hz, and the power spectral density of the frequency noise reaches 7.69×10-8 Hz2/Hz at 10 Hz. Finally, the relative measurement accuracy of 1.39×10-9 is achieved by this loop and the free spectral range coefficient of thermal expansion is measured as -174.1±0.2 Hz/°C with a cavity finesse of 26.65. This work provides a method to measure free spectral range by tracking the resonance modes of the resonator and reducing frequency noise, especially for two signals with frequency offset.