Optical feedback frequency locking: impact of directly reflected field and responding strategies.

The challenges presented by the directly reflected field in optical feedback cavity-enhanced spectroscopy systems serve as substantial obstacles, introducing additional complexity to existing systems and compromising their sensitivity, as the underlying mechanisms of its adverse effects remain not fully understood. This study aims to address this issue by introducing a comprehensive analytical model. Additionally, frequency locking can be achieved by decreasing the feedback rate, the laser's linewidth enhancement factor, and the directly reflected field, and by increasing the refractive index of the gain medium, the length of the laser's resonant cavity, the electric field reflectivity of the laser's output facet, and the resonant field. These parameters can affect the feedback coupling rate pre-factor, and for a resonant cavity with a length of 0.394 m, optical feedback can only be established when the feedback coupling rate pre-factor is less than 1.05 × 109. Through experimental validation, we successfully confirm the effectiveness of the proposed solution in eliminating the detrimental effects of the directly reflected field. Importantly, this suppression is achieved without compromising other aspects of the system's performance. The research findings not only offer the potential to optimize various cavity-enhanced spectroscopy systems that rely on optical feedback but also show promising applications in advancing the development of high-purity spectrum diode lasers utilizing optical feedback from an external high-finesse cavity.

Phase-Modified Strongly Coupled δ/ε-MnO2 Homojunction Cathode for Kinetics-Enhanced Zinc-Ion Batteries.

Rechargeable Zn-MnO2 batteries using mild water electrolytes have garnered significant interest owing to their impressive theoretical energy density and eco-friendly characteristics. However, MnO2 suffers from huge structural changes during the cycles, resulting in very poor stability at high charge-discharge depths. Briefly, the above problems are caused by slow kinetic processes and the dissolution of Mn atoms in the cycles. In this paper, a 2D homojunction electrode material (δ/ε-MnO2) based on δ-MnO2 and ε-MnO2 has been prepared by a two-step electrochemical deposition method. According to the DFT calculations, the charge transfer and bonding between interfaces result in the generation of electronic states near the Fermi surface, giving δ/ε-MnO2 a more continuous distribution of electron states and better conductivity, which is conducive to the rapid insertion/extraction of Zn2+ and H+. Moreover, the strongly coupled Mn-O-Mn interfacial bond can effectively impede dissolution of Mn atoms and thus maintain the structural integrity of δ/ε-MnO2 during the cycles. Accordingly, the δ/ε-MnO2 cathode exhibits high capacity (383 mAh g-1 at 0.1 A g-1), superior rate performance (150 mAh g-1 at 5 A g-1), and excellent cycling stability over 2000 cycles (91.3% at 3 A g-1). Profoundly, this unique homojunction provides a novel paradigm for reasonable selection of different components.

Estrogen receptor ß and treatment with a phytoestrogen are associated with inhibition of nuclear translocation of EGFR in the prostate.

Knockout of ERß in the mouse leads to nuclear expression of epidermal growth factor receptor (EGFR) in the prostate. To examine whether ERß plays a similar role in the human prostate, we used four cohorts of men: 1) a Swedish cohort of normal prostates and PCa (prostate cancer) of different Gleason grades; 2) men with benign prostatic hyperplasia (BPH) treated with the 5α-reductase inhibitor, finasteride, and finasteride together with the ERß agonists, soy isoflavones; 3) men with PCa above Gleason grade 4 (GG4), treated with ADT (androgen deprivation therapy) and abiraterone (AA), the blocker of androgen synthesis for different durations; and 4) men with GG4 PCa on ADT or ADT with the AR (androgen receptor) blocker, enzalutamide, for 4 mo to 6 mo. In men with BPH, finasteride treatment induced EGFR nuclear expression, but, when finasteride was combined with isoflavones, EGFR remained on the cell membrane. In GG4 patients, blocking of AR for 4 mo to 6 mo resulted in loss of ERß and PTEN expression and increase in patients with nuclear EGFR from 10 to 40%. In the men with GG4 PCa, blocking of adrenal synthesis of testosterone for 2 mo to 7 mo had the beneficial effect of increasing ERß expression, but, on treatment longer than 8 mo, ERß was lost and EGFR moved to the nucleus. Since nuclear EGFR is a predictor of poor outcome in PCa, addition of ERß agonists together with abiraterone should be considered as a treatment that might sustain expression of ERß and offer some benefit to patients.

Fluorescence Noise Eliminating Fiber-Enhanced Raman Spectroscopy for Simultaneous and Multiprocess Analysis of Intermediate Compositions for C2H2 and H2 Production.

C2H2 and H2, as important chemical and energy raw materials, can be produced effectively and environmentally friendly by the partial oxidation (POX) of CH4. Simultaneous analysis of intermediate gas compositions in the multiprocess (cracking, recovery, degassing, etc) of POX can regulate product generation and improve production efficiency. To overcome the disadvantage of common gas chromatography, we propose a fluorescence noise eliminating fiber-enhanced Raman spectroscopy (FNEFERS) technique for simultaneous and multiprocess analysis of the POX process, in which the fluorescence noise eliminating (FNE) method can effectively eliminate the horizontal and vertical spatial noise to ensure ppm level limits of detection (LOD). The vibration modes of gas compositions related to each POX process such as cracked gas, synthesis gas, and product acetylene are analyzed. Meanwhile, the composition of three-process intermediate sample gases from Sinopec Chongqing SVW Chemical Co., Ltd is quantitatively and qualitatively analyzed simultaneously, along with the ppm level LODs (H2: 11.2 ppm, C2H2: 3.1 ppm, CO2: 9.4 ppm, C2H4: 4.8 ppm, CH4: 1.5 ppm, CO: 17.9 ppm, allene: 1.5 ppm, methyl acetylene: 2.6 ppm, 1,3-butadiene: 2.8 ppm) with a laser power of 180 mW, exposure time of 30 s, and accuracy of higher than 95.2%. This study fully demonstrates the ability of FNEFERS to replace gas chromatography to achieve simultaneous and multiprocess analysis of intermediate compositions for C2H2 and H2 production and to monitor other chemical and energy production processes.

Simple technique of coupling a diode laser into a linear power buildup cavity for Raman gas sensing.

We report a novel, to the best of our knowledge, and simple technique to lock a 642 nm multi-quantum well diode laser to an external linear power buildup cavity by directly feeding the cavity reflected light back to the diode laser for enhancement of gas Raman signals. The dominance of the resonant light field in the locking process is achieved by reducing the reflectivity of the cavity input mirror and thus making the intensity of the directly reflected light weaker than that of the resonant light. Compared with traditional techniques, stable power buildup in the fundamental transverse mode TEM00 is guaranteed without any additional optical elements or complex optical arrangements. An intracavity exciting light of 160 W is generated with a 40 mW diode laser. Using a backward Raman light collection geometry, detection limits at the ppm level are achieved for ambient gases (N2, O2) with an exposure time of 60 s.

Ventral prostate and mammary gland phenotype in mice with complete deletion of the ERß gene.

Disagreements about the phenotype of estrogen receptor ß (ERß) knockout mouse, created by removing the DNA-binding domain of the ERß gene or interruption of the gene with a neocassette (Oliver Smithies ERß knockout mice [ERßOS-/-]), prompted us to create an ERß knockout mouse by deleting the ERß gene with the use of CRISPR/Cas9 technology. We confirmed that the ERß gene was eliminated from the mouse genome and that no ERß mRNA or protein was detectable in tissues of this mouse. Overall the phenotype of the ventral prostate (VP) and mammary gland (MG) in ERßcrispr-/- mice was similar to, but more severe than, that in the ERßOS-/-mice. In the VP of 6-mo-old ERßcrispr-/- mice there was epithelial hyperplasia, fibroplasia, inflammation, stromal overgrowth, and intraductal cancer-like lesions. This was accompanied by an increase in Ki67 and P63 and loss in DACH1 and PURα, two androgen receptor (AR) repressors. In the MG there was overexpression of estrogen receptor α and progesterone receptor, loss of collagen, increase in proliferation and expression of metalloproteases, and invasive epithelium. Surprisingly, by 18 mo of age, the number of hyperplastic foci was reduced, the ducts of the VP and MG became atrophic, and, in the VP, there was massive immune infiltration and massive desquamation of the luminal epithelial cells. These changes were coincident with reduced levels of androgens in males and estrogens in females. We conclude that ERß is a tumor suppressor gene in the VP and MG where its loss increases the activity AR and ERα, respectively.

Dense-pattern multi-pass cavity based on spherical mirrors in a Z-shaped configuration for Raman gas sensing.

We report a dense-pattern multi-pass cavity (MPC) based on four spherical mirrors placed in a Z-shaped cavity configuration for improving the Raman signals from gases. The folding structure of the cavity causes dense patterns of spots, and at least 420 beams are reflected in the cavity. Raman spectra of ambient air, methane, and ethylene are recorded to demonstrate the performance of our apparatus. At atmospheric pressure, ppm-level detection limits of the gases are achieved with 10 s of exposure time. The Raman signal intensities of the gases show excellent linearity with the gases' partial pressures, which means that high-accuracy detection is also feasible.

New insights into precocious puberty and ADHD: a nationwide cohort study.

BACKGROUND: Attention deficit-hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders in children; however, studies delineating the association between ADHD and central precocious puberty are limited. This study aimed to understand whether children with ADHD are at a higher risk of central precocious puberty. METHODS: This population-based retrospective cohort study was conducted using the National Health Insurance Research Database of Taiwan to investigate the association between ADHD and the incidence of central precocious puberty between 2000-2015. We identified ADHD individuals treated with methylphenidate, atomoxetine or not. The control cohort consisted of individuals without ADHD. The outcome measure was central precocious puberty diagnosis. RESULTS: Among 290,148 children (mean age: 5.83 years), central precocious puberty incidence was 4.24 and 1.95 per 105 person-years in the ADHD and control groups, respectively. Children with ADHD treated with medication had a higher risk than those without ADHD. However, medication use did not affect the incidence of central precocious puberty among children with ADHD. CONCLUSION: This study showed an association between ADHD and a higher risk of central precocious puberty. Early referral of children with ADHD to a pediatric endocrinologist for evaluation may facilitate correct diagnoses and early interventions. IMPACT: ADHD is associated with a higher risk of central precocious puberty. This study provides relevant findings, as it is the first nationwide, population-based cohort study to investigate the association between ADHD and the risk of central precocious puberty with a 15-year follow-up. Early referral of children with ADHD to a pediatric endocrinologist for the evaluation of suspected precocious puberty could facilitate correct diagnosis. Early intervention treatment with gonadotropin-releasing hormone agonist might improve final height in children with central precocious puberty.

Association of periodontitis with tinnitus: A population-based cohort study in Taiwan.

AIM: Tinnitus, ringing in the ears, is speculated to be driven by inflammation. This study examined whether periodontitis is a risk factor for tinnitus using Taiwan's National Health Insurance Research Database. MATERIALS AND METHODS: Among the 79,456 patients who visited for dental concerns, 11,055 patients who were diagnosed with periodontitis and underwent periodontal treatment between 2000 and 2015 were enrolled in Group 1. After matching for sex, age, and index year, 11,055 patients with periodontitis who received no treatment were enrolled in Group 2. Similarly, 11,055 participants without periodontitis were included as controls. RESULTS: At the end of the follow-up, 412 and 404 participants in the two periodontitis groups and 321 participants in the control group had tinnitus. Cumulative risk for tinnitus in Group 1 or 2 was significantly greater than in the control group. More periodontitis patients than controls developed tinnitus (adjusted hazard ratios were 1.71 (95% confidence interval [CI]: 1.49-1.97, p < .001) and 1.64 (95% CI: 1.37-1.86, p < .001) in Groups 1 and 2, respectively). The risks were not significantly different between Groups 1 and 2. Similar findings were obtained after excluding data for the first 1 or 5 years. CONCLUSIONS: The study findings indicate that periodontitis is associated with tinnitus.

Retinal and optic nerve degeneration in liver X receptor ß knockout mice.

The retina is an extension of the brain. Like the brain, neurodegeneration of the retina occurs with age and is the cause of several retinal diseases including optic neuritis, macular degeneration, and glaucoma. Liver X receptors (LXRs) are expressed in the brain where they play a key role in maintenance of cerebrospinal fluid and the health of dopaminergic neurons. Herein, we report that LXRs are expressed in the retina and optic nerve and that loss of LXRß, but not LXRα, leads to loss of ganglion cells in the retina. In the retina of LXRß-/- mice, there is an increase in amyloid A4 and deposition of beta-amyloid (Aß) aggregates but no change in the level of apoptosis or autophagy in the ganglion cells and no activation of microglia or astrocytes. However, in the optic nerve there is a loss of aquaporin 4 (AQP4) in astrocytes and an increase in activation of microglia. Since loss of AQP4 and microglial activation in the optic nerve precedes the loss of ganglion cells, and accumulation of Aß in the retina, the cause of the neuronal loss appears to be optic nerve degeneration. In patients with optic neuritis there are frequently AQP4 autoantibodies which block the function of AQP4. LXRß-/- mouse is another model of optic neuritis in which AQP4 antibodies are not detectable, but AQP4 function is lost because of reduction in its expression.

CircSmg5 stimulates the osteogenic differentiation of bone marrow mesenchymal stem cells by targeting the miR-194-5p/Fzd6 axis and beta-catenin signaling.

BACKGROUND: Osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) is closely associated with bone diseases. Circular RNAs are reported to be involved in BMSC differentiation. CircSmg5 (circ_0001145) has been identified to be downregulated in an osteoporosis mouse model. In this study, we aimed to explore the function and regulatory mechanism of circSmg5 in BMSC osteogenic differentiation. METHODS: The Alizarin Red staining and alkaline phosphatase staining assays were performed to explore the osteogenic differentiation of BMSCs. The interaction between circ_0001145, miR-194-5p, and frizzled class receptor 6 (Fzd6) was analyzed by luciferase reporter assay. The nuclear translocation of ß-catenin was assessed using immunofluorescence staining. RESULTS: CircSmg5 is in stable circular structure. CircSmg5 expression was elevated in the process of BMSC osteogenic differentiation. CircSmg5 overexpression promoted the osteogenic differentiation of BMSCs. CircSmg5 bound with miR-194-5p, whose expression was decreased in the osteogenic differentiation of BMSCs. MiR-194-5p directly targeted the 3'UTR of Fzd6. The mRNA and protein levels of Fzd6 were positively modulated by circSmg5 and negatively regulated by miR-194-5p in BMSCs. CONCLUSION: CircSmg5 was demonstrated to promote the BMSC osteogenic differentiation by targeting the miR-194-5p/Fzd6 axis to activate the Wnt/ß-catenin signaling.

Vibrational Spectra and Molecular Vibrational Behaviors of Dibenzyl Disulfide, Dibenzyl Sulphide and Bibenzyl.

The vibration spectroscopy (Raman and infrared) of widely concerned molecules in sulfur corrosion phenomenon (Dibenzyl Disulfide, Dibenzyl Sulphide, and Bibenzyl) is detailedly analyzed based on density functional theory and experimental measurement. The dominant conformations of these molecules are determined according to Boltzmann distribution in relative Gibbs free energy. Additionally, noncovalent interaction analysis is conducted to indicate intramolecular interaction. Vibration normal mode is assigned based on potential energy distribution, which comprehensively reveals the molecular vibrational behaviors. Conformations weighted spectra are obtained and compared with experimentally measured spectra. We found that experimental spectra are in good agreement with the theoretical spectra in B3LYP-D3(BJ)/6-311G** level with a frequency correction factor. Furthermore, the divergence among these molecules is discussed. The vibrational behavior of the methylene group in the molecule shows a trend with the presence of the sulfur atom.

Quantitative Analysis of Acetone in Transformer Oil Based on ZnO NPs@Ag NWs SERS Substrates Combined with a Stoichiometric Model.

Acetone is an essential indicator for determining the aging of transformer insulation. Rapid, sensitive, and accurate quantification of acetone in transformer oil is highly significant in assessing the aging of oil-paper insulation systems. In this study, silver nanowires modified with small zinc oxide nanoparticles (ZnO NPs@Ag NWs) were excellent surface-enhanced Raman scattering (SERS) substrates and efficiently and sensitively detected acetone in transformer oil. Stoichiometric models such as multiple linear regression (MLR) models and partial least square regressions (PLS) were investigated to quantify acetone in transformer oil and compared with commonly used univariate linear regressions (ULR). PLS combined with a preprocessing algorithm provided the best prediction model, with a correlation coefficient of 0.998251 for the calibration set, 0.997678 for the predictive set, a root mean square error in the calibration set (RMSECV = 0.12596 mg/g), and a prediction set (RMSEP = 0.11408 mg/g). For an acetone solution of 0.003 mg/g, the mean absolute percentage error (MAPE) was the lowest among the three quantitative models. For a concentration of 7.29 mg/g, the MAPE was 1.60%. This method achieved limits of quantification and detections of 0.003 mg/g and 1 µg/g, respectively. In general, these results suggested that ZnO NPs@Ag NWs as SERS substrates coupled with PLS simply and accurately quantified trace acetone concentrations in transformer oil.

Hazardous Gas Detection by Cavity-Enhanced Raman Spectroscopy for Environmental Safety Monitoring.

We demonstrate the practicability of cavity-enhanced Raman spectroscopy (CERS) with a folded multipass cavity as a unique tool for the detection of hazardous gases in the atmosphere. A four-mirror Z-sharped multipass cavity results in a greatly extended laser-gas interaction length to improve the Raman signal intensity of gases. For Raman intensity maximization, the optimal number of intracavity beams of a single reflection cycle is calculated and then the cavity parameters are designed. A total of 360 intracavity beams are realized, which are circulated four times in the cavity based on the polarization. ppb-Level Raman gas sensing at atmospheric pressure for several typical explosive gases and toxic gases in ambient air, including hydrogen (H2), methane (CH4), carbon monoxide (CO), hydrogen sulfide (H2S), and chlorine (Cl2), is achieved at 300 s exposure time. Our CERS apparatus, which can detect multiple gases simultaneously with ultrahigh sensitivity and high selectivity, is powerful for detecting hazardous gases in the atmosphere, and it has excellent potential for environmental safety monitoring.

Multiple reflections enhanced fiber-optic photoacoustic sensor for gas micro-leakage.

A multiple reflections-enhanced fiber-optic photoacoustic (PA) gas sensor for gas micro-leakage is introduced. Multiple reflections of the excitation laser occur on the inner surface of a reflective ring to enhance the PA signal. The PA signal is obtained by measuring the deflection of the gold-coated poly (phenylene sulfide) (PPS) diaphragm with a Fabry-Perot interferometer (FPI). The second harmonic wavelength modulation spectrum (2f-WMS) technology can essentially eliminate the fundamental frequency noise generated by the wavelength-independent absorption of the reflective ring. Experimental results show that the PA signal can be effectively enhanced 11.7 times by the multiple reflections optical path compare with the double-pass optical path. The minimum detection limit of the system is achieved to be 23.6 ppb. The designed PA gas sensor is suited for remote detection of gas micro-leakage.

Fiber-enhanced Raman spectroscopy for highly sensitive H2 and SO2 sensing with a hollow-core anti-resonant fiber.

An innovative fiber-enhanced Raman gas sensing system with a hollow-core anti-resonant fiber is introduced. Two iris diaphragms are implemented for spatial filtering, and a reflecting mirror is attached to one fiber end that provides a highly improved Raman signal enhancement over 2.9 times than the typical bare fiber system. The analytical performance for multigas compositions is thoroughly demonstrated by recording the Raman spectra of carbon dioxide (CO2), oxygen (O2), nitrogen (N2), hydrogen (H2), and sulfur dioxide (SO2) with limits of detection down to low-ppm levels as well as a long-term instability < 1.05%. The excellent linear relationship between Raman signal intensity (peak height) and gas concentrations indicates a promising potential for accurate quantification.

Motor Function Deficits in the Estrogen Receptor Beta Knockout Mouse: Role on Excitatory Neurotransmission and Myelination in the Motor Cortex.

BACKGROUND: Male estrogen receptor beta (ERß) knockout (BERKO) mice display anxiety and aggression linked to, among others, altered serotonergic signaling in the basolateral amygdala and dorsal raphe, impaired cortical radial glia migration, and reduced GABAergic signaling. The effects on primary motor cortex (M1 cortex) and locomotor activity as a consequence of ERß loss have not been investigated. OBJECTIVE: The aim of this study was to determine whether locomotor activity is altered as a consequence of the changes in the M1 cortex. METHODS: The locomotor activity of male wild-type (WT) and BERKO mice was evaluated using the open-field and rotarod tests. Molecular changes in the M1 cortex were analyzed by RNA sequencing, electron microscopy, electrophysiology, and immunohistological techniques. In addition, we established oligodendrocyte (OL) cultures from WT and BERKO mouse embryonic stem cells to evaluate OL function. RESULTS: Locomotor profiling revealed that BERKO mice were more active than WT mice but had impaired motor coordination. Analysis of the M1 cortex pointed out differences in synapse function and myelination. There was a reduction in GABAergic signaling resulting in imbalanced excitatory and inhibitory neurotransmission as well as a defective OL differentiation accompanied by myelin defects. The effects of ERß loss on OL differentiation were confirmed in vitro. CONCLUSION: ERß is an important regulator of GABAergic interneurons and OL differentiation, which impacts on adult M1 cortex function and may be linked to increased locomotor activity and decreased motor coordination in BERKO mice.

A metabolomic approach to elucidate the inhibitory effects of baicalin in pulmonary fibrosis.

CONTEXT: Baicalin, a major flavonoid extracted from Scutellaria baicalensis Georgi (Lamiaceae), has been shown to exert therapeutic effects on pulmonary fibrosis (PF). OBJECTIVE: To use serum metabolomics combined with biochemical and histopathological analyses to clarify anti-PF mechanisms of baicalin on metabolic pathways and the levels of potential biomarkers. MATERIALS AND METHODS: Forty male Sprague-Dawley rats were randomly divided into the control, PF model, prednisolone acetate-treated (4.2 mg/kg/day) and baicalin-treated (25 and 100 mg/kg/day) groups. A rat model of PF was established using a tracheal injection of bleomycin, and the respective drugs were administered intragastrically for 4 weeks. Histomorphology of lung tissue was examined after H&E and Masson's trichrome staining. Biochemical indicators including SOD, MDA and HYP were measured. Serum-metabonomic analysis based on UPLC-Q-TOF/MS was used to clarify the changes in potential biomarkers among different groups of PF rats. RESULTS: Both doses of baicalin effectively alleviated bleomycin-induced pathological changes, and increased the levels of SOD (from 69.48 to 99.50 and 112.30, respectively), reduced the levels of MDA (from 10.91 to 5.0 and 7.53, respectively) and HYP (from 0.63 to 0.41 and 0.49, respectively). Forty-eight potential biomarkers associated with PF were identified. Meanwhile, the metabolic profiles and fluctuating metabolite levels were normalized or partially reversed after baicalin treatment. Furthermore, baicalin was found to improve PF potentially by the regulation of four key biomarkers involving taurine and hypotaurine metabolism, glutathione metabolism, and glycerophospholipid metabolism. CONCLUSIONS: These findings revealed the anti-fibrotic mechanisms of baicalin and it may be considered as an effective therapy for PF.

Metabolomic assessment of mechanisms underlying anti-renal fibrosis properties of petroleum ether extract from Amygdalus mongolica.

CONTEXT: The petroleum ether extract (PET) of Amygdalus mongolica (Maxim.) Ricker (Rosaceae) has an ameliorative effect on renal fibrosis (RF). OBJECTIVE: To evaluate the antifibrotic effects of A. mongolica seeds PET on RF by serum metabolomics, biochemical and histopathological analyses. MATERIALS AND METHODS: Sixty male Sprague-Dawley rats were randomly divided into the sham-operated, RF model, benazepril hydrochloride-treated model (1.5 mg/kg) and PET-treated (1.75, 1.25, 0.75 g/kg) groups, and the respective drugs were administered intragastrically for 21 days. Biochemical indicators including BUN, Scr, HYP, SOD, and MDA were measured. Haematoxylin and eosin and Masson staining were used for histological examination. The serum metabolomic profiles were determined by UPLC-Q-TOF/MS and metabolism network analysis. Acute toxicity test was performed to validate biosafety. RESULTS: The PET LD50 was >23.9 g/kg in rats. PET significantly alleviated fibrosis by reducing the levels of Scr (from 34.02 to 32.02), HYP (from 403.67 to 303.17) and MDA (from 1.84 to 1.73), and increasing that of SOD (from 256.42 to 271.85). Metabolomic profiling identified 10 potential biomarkers, of which three key markers were significantly associated with RF-related pathways including phenylalanine, tyrosine and tryptophan biosynthesis, amino sugar and nucleotide sugar metabolism and tyrosine metabolism. In addition, three key biomarkers were restored to baseline levels following PET treatment, with the medium dose showing optimal effect. CONCLUSIONS: These findings revealed the mechanism of A. mongolica PET antifibrotic effects for RF rats on metabolic activity and provided the experimental basis for the clinical application.

Multigas Analysis by Cavity-Enhanced Raman Spectroscopy for Power Transformer Diagnosis.

We demonstrate the utility of cavity-enhanced Raman spectroscopy (CERS) as a unique multigas analysis tool for power transformer diagnosis. For this purpose, improvements have been added to our recently introduced CERS apparatus. Based on optical feedback frequency-locking, laser radiation is coupled into a high-finesse optical cavity, thus resulting in huge intracavity laser power. With 20 s exposure time, ppm-level gas sensing at 1 bar total pressure is achieved, including carbon dioxide (CO2), carbon monoxide (CO), hydrogen (H2), methane (CH4), ethane (C2H6), ethylene (C2H4), acetylene (C2H2), nitrogen (N2), and oxygen (O2). By using the internal standard gas (sulfur hexafluoride, SF6), the quantification of multigas with high accuracy is also realized, which is confirmed by the measurement of calibration gases. For fault diagnosis, transformer oil is sampled from a 110 kV power transformer in service. Dissolved gases are extracted and analyzed by the CERS apparatus. Then the transformer is diagnosed according to the measurement results. CERS has the ability to analyze multigas with high selectivity, sensitivity, and accuracy, it has great potential in gas sensing fields.