Integrated Bioinformatics and Machine Learning Analysis Identify ACADL as a Potent Biomarker of Reactive Mesothelial Cells.

Mesothelial cells with reactive hyperplasia are difficult to distinguish from malignant mesothelioma cells on cell morphology. This study aimed to identify and validate potential biomarkers that distinguish mesothelial cells from mesothelioma cells through machine learning combined with immunohistochemistry experiments. This study integrated the gene expression matrix from three Gene Expression Omnibus data sets (GSE2549, GSE12345, and GSE51024) to analyze the differently expressed genes between normal and mesothelioma tissues. Then, three machine learning algorithms, least absolute shrinkage and selection operator, support vector machine-recursive feature elimination, and random forest were used to screen and obtain four shared candidate markers, including ACADL, EMP2, GPD1L, and HMMR. The receiver operating characteristic curve analysis showed that the area under the curve for distinguishing normal from mesothelioma was 0.976, 0.943, 0.962, and 0.956, respectively. The expression and diagnostic performance of these candidate genes were validated in another two independent data sets (GSE42977 and GSE112154), indicating that the performances of ACADL, GPD1L, and HMMR were consistent between the training and validation data sets. Finally, the optimal candidate marker ACADL was verified by immunohistochemistry assay. ACADL was stained strongly in mesothelial cells, especially for reactive hyperplasic mesothelial cells, but was negative in malignant mesothelioma cells. Therefore, ACADL has the potential to be used as a specific marker of reactive hyperplasic mesothelial cells in the differential diagnosis of mesothelioma.

Relationship between the baking quality of wheat (Triticum aestivum L.) and the protein composition and structure after shading.

Although wheat (Triticum aestivum L.) grain protein content is increased by shade stress, the relationship between the baking quality of wheat flour and protein composition and structure remains unclear. Here, we investigated the effects of shade stress on wheat flour protein composition and structure. The contents of the flour protein, α/ß-gliadins and disulfide and hydrogen bonds were significantly increased by shade stress. Glutenins, UPP%, and ß-sheet contents also increased, whereas that of α-helices decreased. Spearman correlations revealed that the flour protein content, Glu:Gli ratio, and disulfide, hydrogen, and ionic bonds can predict the specific volume and number of crumb cells in bread, whereas α/ß-gliadins content can predict the crumb cell wall thickness and diameter of bread. Under shade stress, variations in protein composition and structure help increase the specific volume and crumb cells number and decrease crumb cell wall thickness and diameter of bread, ultimately leading to improved baking quality.

Regulating the composition and secondary structure of wheat protein through canopy shading to improve dough performance and nutritional index.

Viscoelastic properties of gluten proteins critically determine the biscuit-making quality. However, cultivar genetics and light conditions closely regulate the composition of the gluten proteins. The impact of pre- and post-anthesis shading (60 %) on amino acid profile, gluten protein composition, secondary structure, dough performance, and biscuit-making quality were evaluated using four wheat cultivars that differ in gluten protein composition. Pre- and post-anthesis shading increased the contents of gliadin, by 35.8 and 3.1 %; glutenin, by 27.6 and 7.3 %; and total protein, by 21.7 and 10.6 %, respectively, compared with those of unshaded plants. Conversely, the ratios of glutenin/gliadin, ω-/(α,ß + Î³)-gliadin, and high-molecular-weight/low-molecular-weight glutenin subunits decreased with shading. Strong-gluten cultivars exhibited smaller declines in these parameters than weak-gluten cultivars. Secondary structure analysis of the wheat protein revealed that shading increased ß-sheet content but decreased ß-turn content. Changes in protein components and their secondary structures caused an increase in wet gluten content, dough development time, and gluten performance index, thereby decreasing the biscuit spread ratio. Shading stress increased the protein content and nutrition index but decreased the biological value of protein by 2.5 %. Transcriptomic results revealed that shading induced 139 differentially expressed genes that decreased carbohydrate metabolism and increased amino acid metabolism, involved in increased protein content. Thus, canopy shading improves dough performance and nutrition index by regulating the amino acid profiles, protein compositions, and secondary structures. The study provides key insights for achieving superior grain quality under global dimming.

Shading affects the starch structure and digestibility of wheat by regulating the photosynthetic light response of flag leaves.

Heavy haze-induced decreases in solar radiation represent an important factor that affects the structural properties of starch macromolecules. However, the relationship between the photosynthetic light response of flag leaves and the structural properties of starch remains unclear. In this study, we investigated the impact of light deprivation (60 %) during the vegetative-growth or grain-filling stage on the leaf light response, starch structure, and biscuit-baking quality of four wheat cultivars with contrasting shade tolerance. Shading decreased the apparent quantum yield and maximum net photosynthetic rate of flag leaves, resulting in a lower grain-filling rate and starch content and higher protein content. Shading decreased the starch, amylose, and small starch granule amount and swelling power but increased the larger starch granule amount. Under shade stress, the lower amylose content decreased the resistant starch content while increasing the starch digestibility and estimated glycemic index. Shading during the vegetative-growth stage increased starch crystallinity, 1045/1022 cm-1 ratio, starch viscosity, and the biscuit spread ratio, while shading during the grain-filling stage decreased these values. Overall, this study indicated that low light affects the starch structure and biscuit spread ratio by regulating the photosynthetic light response of flag leaves.

The Tumorigenic Effect of the High Expression of Ladinin-1 in Lung Adenocarcinoma and Its Potential as a Therapeutic Target.

The oncogenic role of Ladinin-1 (LAD1), an anchoring filament protein, is largely unknown. In this study, we conducted a series of studies on the oncogenic role of LAD1 in lung adenocarcinoma (LUAD). Firstly, we analyzed the aberrant expression of LAD1 in LUAD and its correlation with patient survival, tumor immune infiltration, and the activation of cancer signaling pathways. Furthermore, the relationship between LAD1 expression and K-Ras and EGF signaling activation, tumor cell proliferation, migration, and colony formation was studied by gene knockout/knockout methods. We found that LAD1 was frequently overexpressed in LUAD, and high LAD1 expression predicts a poor prognosis. LAD1 exhibits promoter hypomethylation in LUAD, which may contribute to its mRNA upregulation. Single-sample gene set enrichment analysis (ssGSEA) showed that acquired immunity was negatively correlated with LAD1 expression, which was verified by the downregulated GO terms of "Immunoglobulin receptor binding" and "Immunoglobulin complex circulating" in the LAD1 high-expression group through Gene Set Variation Analysis (GSVA). Notably, the Ras-dependent signature was the most activated signaling in the LAD1 high-expression group, and the phosphorylation of downstream effectors, such as ERK and c-jun, was strongly inhibited by LAD1 deficiency. Moreover, we demonstrated that LAD1 depletion significantly inhibited the proliferation, migration, and cell-cycle progression of LUAD cells and promoted sensitivity to Gefitinib, K-Ras inhibitor, and paclitaxel treatments. We also confirmed that LAD1 deficiency remarkably retarded tumor growth in the xenograft model. Conclusively, LAD1 is a critical prognostic biomarker for LUAD and has potential as an intervention target.

A prediction model for prognosis of gastric adenocarcinoma based on six metabolism-related genes.

Background: The study of tumor metabolism is of great value to elucidate the mechanism of tumorigenesis and predict the prognosis of patients. However, the prognostic role of metabolism-related genes (MRGs) in gastric adenocarcinoma (GAD) remains poorly understood. Methods: We downloaded the gene chip dataset GSE79973 (n = 20) of GAD from the Gene Expression Omnibus (GEO) database to compare differentially expressed genes (DEGs) between normal and tumor tissues. We then extracted MRGs from these DEGs and systematically investigated the prognostic value of these differential MRGs for predicting patients' overall survival by univariable and multivariable Cox regression analysis. Six metabolic genes (ACOX3, APOE, DIO2, HSD17B4, NUAK1, and WHSC1L1) were identified as prognosis-associated hub genes, which were used to build a prognostic model in the training dataset GSE15459 (n = 200), and then validated in the dataset GSE62254 (n = 300). Results: Patients were divided into high-risk and low-risk subgroups based on the model's risk score, and it was found that patients in the high-risk subgroup had shorter overall survival than those in the low-risk subgroup, both in the training and testing datasets. In addition, for the training and testing cohorts, the area under the ROC curve of the prognostic model for one-year survival prediction was 0.723 and 0.667, respectively, indicating that the model has good predictive performance. Furthermore, we established a nomogram based on tumor stage and risk score to effectively predict the overall survival (OS) of GAD patients. The expression of 6 MRGs at the protein level was confirmed by immunohistochemistry (IHC). Kaplan-Meier survival analysis further confirmed that their expression influenced OS in GAD patients. Conclusion: Collectively, the 6 MRGs signature might be a reliable tool for assessing OS in GAD patients, with potential application value in clinical decision-making and individualized therapy.

Straw Mulching and Nitrogen Fertilization Affect Diazotroph Communities in Wheat Rhizosphere.

Diazotrophs that carry out the biological fixation of atmospheric dinitrogen (N2) replenish biologically available nitrogen (N) in soil and are influenced by the input of inorganic and organic substrates. To date, little is known about the effects of combined organic substrate addition and N fertilization on the diazotroph community composition and structure in purple soils. We investigated the effects of N fertilization and straw mulching on diazotroph communities by quantifying and sequencing the nifH gene in wheat rhizosphere. The abundance and richness of diazotrophs were greater the higher the fertilization level in the mulched treatments, whereas in the nonmulched treatments (NSMs), richness was lowest with the highest N fertilization level. The abundance and α-diversity of diazotrophs correlated with most of the soil properties but not with pH. At the genus level, the relative abundances of Azospirillum, Bacillus, and Geobacter were higher in the NSMs and those of Pseudacidovorax, Skermanella, Azospira, Paraburkholderia, Azotobacter, Desulfovibrio, Klebsiella, and Pelomonas in the mulched treatments. The differences in community composition between the mulched and the NSMs were associated with differences in soil temperature and soil organic carbon and available potassium contents and C:N ratio. Overall, straw mulching and N fertilization were associated with changes in diazotroph community composition and higher abundance of nifH gene in alkaline purple soils.

Streptomyces aquilus sp. nov., a novel actinomycete isolated from a Chinese medicinal plant.

The taxonomic position of a novel actinomycete isolate, designated strain GGCR-6T, isolated from the healthy leaves of Xanthium sibiricum collected from the botanic garden of Hunan University of Science and Technology in Hunan province, PR China, was determined by a polyphasic approach. GGCR-6T grew well on ISP series media and formed well-developed, branched substrate hyphae and aerial mycelium that differentiated into straight spore chains consisting of cylindrical spores with smooth surfaces. The diagnostic diamino acid was ll-diaminopimelic acid. The major menaquinones were MK-9(H8), MK-9(H2), MK-9 and MK-9(H6). The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphotidylinositol and phosphatidylinositol mannosides. The predominant fatty acids were C16 : 1ω9c, iso-C16 : 0 and C16 : 0. The phenotypic characteristics of GGCR-6T indicated that it represented a member of the genus Streptomyces. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that GGCR-6T was most closely related to Streptomyces cyaneus NRRL B2296T and Streptomyces griseoruber NRRL B1818T. However, the digital DNA-DNA hybridization, the average nucleotide identity and the multi locus sequence analysis evolutionary distance clearly separate GGCR-6T from the phylogenetically closely related species. Furthermore, the novel isolate was distinctly differentiated from S. cyaneus NRRL B2296T and S. griseoruber NRRL B1818T by morphological, physiological and biochemical characteristics. Based on these data, strain GGCR-6T should be designated as a representative of a novel species of the genus Streptomyces, for which the name Streptomyces aquilus sp. nov. is proposed. The type strain is strain GGCR-6T (=CICC 11055T=JCM 33584T).

[Effect of Sini San prescription on apoptosis and proliferation of hepatocellular carcinoma HepG2 cells].

Objective: To investigate the effects of Sini San prescription(SNS) on the proliferation and apoptosis of HepG2 cells and its molecular mechanism. Methods: The morphological changes of hepatocellular carcinoma HepG2 cells treated by SNS were observed by inverted microscope. MTT assay was used to detect the inhibitory effect of SNS on cell proliferation. Fluorescence staining and flow cytometry were employed to analyze the effect of SNS on apoptosis of HepG2 cells. Rho123 (Rhodamine 123) staining method was performed to detect the changes of mitochondrial membrane potential, and Western blot was used to evaluate the expression of proteins related to apoptosis. Results: The number of hepatocellular carcinoma HepG2 cells were significantly decreased (P＜0.01) and cells showed typical apoptotic cell morphology after treated with serum contained SNS. The inhibition rate of HepG2 cells was increased with the increase of concentration of serum contained SNS. The number of cells in G1 phase was significantly increased, while G2 phase was decreased after treated with serum contained SNS(P＜0.05).The apoptosis rate and mitochondrial membrane potential of HepG2 cells were significantly increased and decreased after treated with serum contained SNS(P＜0.05). The expression levels of Bax, caspase-3,-9 and cyt-c were significantly increased, while the expression of bcl-2 was decreased in HepG2 cells treated with serum contained SNS(P＜0.05).Conclusion: Sini San prescription can inhibit the proliferation of HepG2 cells and induce apoptosis by mitochondrial pathway.

Streptomyces paludis sp. nov., isolated from an alpine wetland soil.

A Gram-stain-positive actinobacterium, designated strain GSSD-12T, was isolated from an alpine wetland soil. blast search of the full-length 16S rRNA gene sequence of GSSD-12T indicated it represented a member of the genus Streptomyces, and displayed highest similarity with Streptomyces scopuliridis NRRL B-24574T (99.2 %) and less than 98.6 % similarity with other species of the genus Streptomyces with validly published names. Phylogenetic analysis based on 16S rRNA gene sequences indicated that GSSD-12T was closely related to S. scopuliridis NRRL B-24574T, Streptomyces odonnellii NRRL B-24891T and Streptomyces lushanensis NRRL B-24994T. However, the digital DNA-DNA hybridization value, the average nucleotide identity value and the multilocus sequence analysis evolutionary distance between this strain and its closest relatives indicated that it represented a distinct species. Furthermore, GSSD-12T was also distinctly differentiated from them by morphological, physiological and biochemical characteristics. Therefore, strain GSSD-12T(=CICC 11051T=JCM 33019T) represents a novel species of the genus Streptomyces, for which the name Streptomyces paludis sp. nov. is proposed.

Genome-Wide Identification and Transcriptional Expression of the METTL21C Gene Family in Chicken.

The chicken is a common type of poultry that is economically important both for its medicinal and nutritional values. Previous studies have found that free-range chickens have more skeletal muscle mass. The methyltransferase-like 21C gene (METTL21C) plays an important role in muscle development; however, there have been few reports on the role of METTL21C in chickens. In this study, we performed a genome-wide identification of chicken METTL21C genes and analyzed their phylogeny, transcriptional expression profile, and real-time quantitative polymerase chain reaction (qPCR). We identified 10 GgMETTL21C genes from chickens, 11 from mice, and 32 from humans, and these genes were divided into six groups, which showed a large amount of variation among these three species. A total of 15 motifs were detected in METTL21C genes, and the intron phase of the gene structure showed that the METTL21C gene family was conservative in evolution. Further, both the transcript data and qPCR showed that a single gene's (GgMETTL21C3) expression level increased with the muscle development of chickens, indicating that the METTL21C genes are involved in the development of chicken muscles. Our results provide some reference value for the subsequent study of the function of METTL21C.

Streptomyces cyaneochromogenes sp. nov., a blue pigment-producing actinomycete from manganese-contaminated soil.

A novel actinomycete isolate, designated strain MK-45T, was isolated from soil sampled at a manganese-contaminated area in Xiangtan, China. The isolate formed extensively branched substrate mycelia and aerial mycelia that differentiated into tightly coiled or spiral spore chains with smooth-surfaced spores. The cell-wall hydrolysates contained ll-diaminopimelic acid and traces of meso-diaminopimelic acid. The major menaquinones consisted of MK-9(H4), MK-9(H6) and MK-9(H8). The major polar lipids contained diphosphatidylgycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphotidylinositol and phosphotidylinositol mannosides. The predominant cellular fatty acids were iso-C16 : 0, C16 : 0 and summed feature 3. Phylogenetic analysis based on the 16S rRNA gene sequences and concatenated partial sequences of the five protein-coding genes indicated that strain MK-45T was a member of the genus Streptomyces and most closely related to Streptomyces caeruleatus GIMN4.002T (99.5 % similarity), Streptomyces curacoi CGMCC 4.1680T (99.5 %), Streptomyces shaanxiensis CCNWHQ 0031T (99.4 %) and Streptomyces cinnabarinus NRRL B12382T (98.9 %), respectively. However, the digital DNA-DNA hybridization values, the average nucleotide identity values and MLSA evolutionary distances between strain MK-45T and them showed that it belonged to a distinct species. Furthermore, the results of morphological, physiological and biochemical tests allowed further phenotypic differentiation of strain MK-45T from the four closely related type strains mentioned above and other species of the genus Streptomyces with which this strain has 98.0-99.2 % 16S rRNA gene sequence similarity. Therefore, it is concluded that strain MK-45T represents a novel species of the genus Streptomyces, for which the name Streptomycescyaneochromogenes sp. nov. is proposed, with MK-45T (=CICC 11045T=KCTC 49099T) as the type strain.

Streptomyces cadmiisoli sp. nov., a novel actinomycete isolated from cadmium-contaminated soil.

A novel Streptomyces strain, ZFG47T, isolated from a cadmium-contaminated soil sample, was taxonomically studied in detail. Strain ZFG47T formed long, flexuous spiral spore chains consisting of elliptoid spores with spiny surfaces. The cell-wall hydrolysates contained ll-diaminopimelic acid as the diagnostic diamino acid. The major menaquinones consisted of MK-9(H2), MK-9(H4) and MK-9(H8). The major polar lipids contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylinositol mannosides. The predominant cellular fatty acids were iso-C16 : 0, C16 : 0 and anteiso-C15 : 0. The 16S rRNA gene sequence-based phylogenetic analysis indicated that this strain belongs to the genus Streptomyces, showing the highest sequence similarity to Streptomyceskoyangensis VK-A60T (98.7 %). However, the digital DNA-DNA hybridization value, the average nucleotide identity value and the MLSA evolutionary distance between this strain and S. koyangensis VK-A60T showed that it belonged to a distinct species. Furthermore, the novel isolate could be distinctly differentiated from S. koyangensis VK-A60T by morphological, physiological and biochemical characteristics. On the basis of the evidence from this polyphasic study, it is concluded that strain ZFG47T represents a novel species of the genus Streptomyces, for which the name Streptomyces cadmiisoli sp. nov. is proposed, with strain ZFG47T (CICC 11050T=JCM 32897T) as the type strain.

The effects and mechanism of peiminine-induced apoptosis in human hepatocellular carcinoma HepG2 cells.

Peiminine is a compound isolated from Bolbostemma paniculatum (Maxim) Franquet (Cucurbitaceae family), which has demonstrated antitumor activities. But its precise molecular mechanism underlying antitumor activity remain elusive. In this study, peiminine-induced apoptosis towards human hepatocellular carcinoma and its molecular mechanism were investigated. MTT assay was employed to assess anticancer effects of peiminine upon Hela, HepG2, SW480 and MCF-7 cell lines. Nuclear staining and flow cytometry were carried out to detect apoptosis induced by peiminine. Mitochondrial membrane potential evaluation and Western blot analysis were performed to investigate the mechanism of peiminine-induced apoptosis. The results showed peiminine reduced the viability of HepG2 cells in a time- and dose-dependent manner and had an IC50 of 4.58 µg/mL at 24h. Peiminine significantly increased the percentage of apoptotic cells and the mitochondrial membrane potential dose-dependently in HepG2 cells. The results of Western blotting indicated the expressions of Bcl-2, procaspase-3, procaspase-8, procaspase-9, and PARP decreased in HepG2 cells treated with peiminine, while the expressions of Bax, caspase-3, caspase-8, caspase-9, and cleaved PARP1 increased. The result suggests that peiminine can induce apoptosis in human hepatocellular carcinoma HepG2 cells through both extrinsic and intrinsic apoptotic pathways.

Streptomyces manganisoli sp. nov., a novel actinomycete isolated from manganese-contaminated soil.

A novel actinomycete isolate, designated strain MK44T, was isolated from a Manganese-polluted soil sample collected near Xiangtan Manganese Mine, South Central China and subjected to a polyphasic taxonomic characterization. Comparison of 16S rRNA gene sequences showed that strain MK44T was a member of the genus Streptomyces and most closely related to Streptomyces specialis JCM 16611T (97.9 %) and Streptomyces mayteni JCM 16957T (97.4 %). The DNA-DNA relatedness between strain MK44T and the above two related type species were 30.9±0.3 and 29.9±3.5 %, respectively, values which are far lower than the 70 % threshold for the delineation of a novel prokaryotic species. Furthermore, the results of physiological, biochemical and chemotaxonomic tests allowed further phenotypic differentiation. Therefore, it is concluded that strain MK44T represents a novel species of the genus Streptomyces, for which the name Streptomyces manganisoli sp. nov. is proposed. The type strain is MK44T (=GDMCC 4.137T=KCTC 39920T).

Streptomyces xiangtanensis sp. nov., isolated from a manganese-contaminated soil.

An actinomycete strain, designated strain LUSFXJT, was isolated from a soil sample obtained near the Xiangtan Manganese Mine, Central-South China and characterised using a polyphasic taxonomic approach. The 16S rRNA gene sequence-based phylogenetic analysis indicated that this strain belongs to the genus Streptomyces. The DNA-DNA relatedness between this strain and two closely related type strains, Streptomyces echinatus CGMCC 4.1642T and Streptomyces lanatus CGMCC 4.137T, were 28.7 ± 0.4 and 19.9 ± 2.0%, respectively, values which are far lower than the 70% threshold for the delineation of a novel prokaryotic species. The DNA G+C content of strain LUSFXJ T is 75.0 mol%. Chemotaxonomic analysis revealed that the menaquinones of strain LUSFXJT are MK-9(H6), MK-9(H8), MK-9(H2) and MK-8(H8). The polar lipid profile of strain LUSFXJT was found to contain diphosphatidylglycerol and an unidentified polar lipid. The major cellular fatty acids were identified as iso-C15:0, anteiso-C15:0, iso-C16:0, C16:0 and Summed feature 3. Strain LUSFXJT was found to contain meso-diaminopimelic acid as the diagnostic cell wall diamino acid and the whole cell hydrolysates were found to be rich in ribose, mannose and glucose. Based on phenotypic, phylogenetic and chemotaxonomic characteristics, it is concluded that strain LUSFXJT represents a novel species of the genus Streptomyces, for which the name S. xiangtanensis sp. nov. is proposed. The type strain is LUSFXJT (=GDMCC 4.133T = KCTC 39829T).

[Immunosuppression effect of co-infection with MDRV and H9 AIV on thymus in muscovy ducks].

OBJECTIVE: To study the immunosuppression effect on the thymus of muscovy ducks after infected with muscovy duck reovirus (MDRV) and H9 influenza virus (AIV). METHODS: After 8-day-old birds were infected with MDRV or H9 AIV, or both, the morbidity and mortality were totaled, the morphology and ultra-structure of the thymus were observed, proliferation ability of thymus cell were detected and the virus distrubition were detected by RT-PCR. RESULTS: After H9 AIV infection, The morbidity was low (10%) and without death. No obvious pathological change was observed on the thymus, whereas the proliferation ability of thymus cell was obviously suppressed. After MDRV infection, The birds grew slow, the morbidity was 80% and mortality was 50%. Thymus was atrophy appearing local necrosis and proliferation ability of thymus cell was obviously suppressed. After co-infection with MDRV and H9 AIV, the birds grew even slower growth. The morbidity was 90% and mortality was 70%. The thymus was atrophy appearing the lymphopenia and local necrosis and proliferation ability of thymus cell was also more obviously suppressed than MDRV infection. Virus duration time and detection ratio in co-infection group were more than in AIV and MDRV group. CONCLUSION: H9 AIV could lead to minor immunosuppression and MDRV could cause serious immuno-suppression. H9 AIV could aggravate the immunosuppression of thymus after co-infected with MDRV, so MDRV and H9 AIV infection had synergic effect on immunosuppression of the thymus.

Extrinsic fiber-optic Fabry-Perot interferometer sensor for refractive index measurement of optical glass.

A simple fiber-optic sensor based on Fabry-Perot interference for refractive index measurement of optical glass is investigated both theoretically and experimentally. A broadband light source is coupled into an extrinsic fiber Fabry-Perot cavity formed by the surfaces of a sensing fiber end and the measured sample. The interference signals from the cavity are reflected back into the same fiber. The refractive index of the sample can be obtained by measuring the contrast of the interference fringes. The experimental data meet with the theoretical values very well. The proposed technique is a new method for glass refractive index measurement with a simple, solid, and compact structure.