Diverse polycyclic polyprenylated acylphloroglucinols with anti-neuroinflammatory activity from Hypericum beanii.

A phytochemical investigation on the roots of Hypericum beanii resulted in the isolation of six new polycyclic polyprenylated acylphloroglucinols (PPAPs), hyperberlones A-F, along with fourteen known analogues. The structural characterization of these compounds was carried out by analyzing the HRESIMS data, 1D and 2D NMR spectroscopic data, electronic circular dichroism (ECD) calculations, and gauge-independent atomic orbital (GIAO) NMR calculations. Hyperberlone A (1) was a caged PPAP with a rare tricyclo[4.3.1.03,8]decane carbon skeleton. It was deduced to be biosynthetically generated from hyperbeanol C (8) through key Paternò-Büchi reaction, radical cascade cyclizations, and retro-aldol reaction. Compounds 4, 6, 7, 9, 14, and 16 exhibited significant nitric oxide (NO) production inhibitory effects in lipopolysaccharide (LPS)-induced BV-2 microglial cells with IC50 values of 6.11-25.28 µM. Moreover, compound 4 significantly decreased the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in LPS-induced BV-2 microglia, as well as the phosphorylation of JNK.

Comparative transcriptomic analysis reveals an association of gibel carp fatty liver with ferroptosis pathway.

BACKGROUND: Fatty liver has become a main problem that causes huge economic losses in many aquaculture modes. It is a common physiological or pathological phenomenon in aquaculture, but the causes and occurring mechanism are remaining enigmatic. METHODS: Each three liver samples from the control group of allogynogenetic gibel carp with normal liver and the overfeeding group with fatty liver were collected randomly for the detailed comparison of histological structure, lipid accumulation, transcriptomic profile, latent pathway identification analysis (LPIA), marker gene expression, and hepatocyte mitochondria analyses. RESULTS: Compared to normal liver, larger hepatocytes and more lipid accumulation were observed in fatty liver. Transcriptomic analysis between fatty liver and normal liver showed a totally different transcriptional trajectory. GO terms and KEGG pathways analyses revealed several enriched pathways in fatty liver, such as lipid biosynthesis, degradation accumulation, peroxidation, or metabolism and redox balance activities. LPIA identified an activated ferroptosis pathway in the fatty liver. qPCR analysis confirmed that gpx4, a negative regulator of ferroptosis, was significantly downregulated while the other three positively regulated marker genes, such as acsl4, tfr1 and gcl, were upregulated in fatty liver. Moreover, the hepatocytes of fatty liver had more condensed mitochondria and some of their outer membranes were almost ruptured. CONCLUSIONS: We reveal an association between ferroptosis and fish fatty liver for the first time, suggesting that ferroptosis might be activated in liver fatty. Therefore, the current study provides a clue for future studies on fish fatty liver problems.

Diverse Polycyclic Polyprenylated Acylphloroglucinol Congeners with Anti-Nonalcoholic Steatohepatitis Activity from Hypericum forrestii.

The new polycyclic polyprenylated acylphloroglucinols, hyperforcinols A-J (1-10), were isolated from the fruits of Hypericum forrestii, together with 30 biogenetic congeners of known structures. The structures of hyperforcinols A-J were determined by HRESIMS and 1D/2D NMR spectroscopic analysis, and their absolute configurations were determined by a combination of the electronic circular dichroism (ECD) exciton chirality method, ECD calculations, and X-ray diffraction analysis. A selection of 25 isolates, possessing seven types of carbon skeletons, were assessed for their in vitro effects against nonalcoholic steatohepatitis (NASH) using a free fatty acid-induced L02 cell model. Compounds 20 and 40 significantly decreased intracellular lipid accumulation. QRT-PCR analyses revealed that compounds 20 and 40 regulate the expression of lipid metabolism-related genes, including CD36, FASN, PPARα, and ACOX1.

Dimethylated acylphloroglucinol meroterpenoids with anti-oral-bacterial and anti-inflammatory activities from Hypericum elodeoides.

Acylphloroglucinol meroterpenoids are adducts of the acylphloroglucinol unit and polyprenylated fragments (terpenoids) with attractive structures and bioactivities. During study of the medicinal molecules of the genus Hypericum, the first example of dimethylated acylphloroglucinol meroterpenoids with pyran-fused 6/6/6 tricyclic skeletons ((+)/(-)-elodeoidols A-F (1-6)), along with three biogenetical homologues (7-9) were isolated from the herbaceous plant of Hypericum elodeoides. Their structures including absolute configurations were then identified by nuclear magnetic resonance (NMR), high resolution electrospray ionization mass spectroscopy (HRESIMS), electronic circular dichroism (ECD) analysis and calculations. The monoterpene moiety of 1-6 were cyclized as two cyclohexanes and fused with a dimethylated acylphloroglucinol unit through an additional ether linkage, which led to an interesting pyran-fused linear or angle type 6/6/6 tricyclic skeleton. Compounds 5, 8 and 9 showed preferable antibacterial activities against three oral bacteria, among the MIC value of (+)-5 was 6.25 µg/ml; Compounds 3, 7 and 8 exhibited significant NO inhibitory activity against LPS induced RAW264.7 cells (IC50: 10.39 ± 0.49 ~ 34.25 ± 2.32 µM).

Differential expression of innate and adaptive immune genes in the survivors of three gibel carp gynogenetic clones after herpesvirus challenge.

BACKGROUND: Accompanied with rapid growth and high density aquaculture, gibel carp has been seriously threatened by Carassius auratus herpesvirus (CaHV) since 2012. In previous study, distinct CaHV resistances and immune responses were revealed in the diseased individuals of three gibel carp gynogenetic clones (A+, F and H). However, little is known about the gene expression changes in the survivors after CaHV challenge, particularly their differences of innate and adaptive immune system between susceptible clone and resistant clone. RESULTS: We firstly confirmed the CaHV carrier state in the survivors of three gibel carp clones after CaHV challenge by evaluating the abundances of five CaHV genes. The assay of viral loads indicated the resistant clone H possessed not only stronger resistance but also higher tolerance to CaHV. Then, 2818, 4047 and 3323 differentially expressed unigenes (DEUs) were screened from the head-kidney transcriptome profiles of survivors compared with controls from clone A+, F and H. GO and KEGG analysis suggested that a persistent immune response might sustain in resistant clone H and F, while susceptible clone A+ had a long-term impact on the circulatory system which was consistent with the major symptoms of bleeding caused by CaHV. Among the top 30 enriched pathways of specifically up-regulated DEUs in respective clones, 26, 7 and 15 pathways in clone H, F and A+ were associated with infections, diseases, or immune-related pathways respectively. In addition, 20 pathways in clone F belonged to "metabolism" or "biogenesis", and 7 pathways involved in "circulatory system" were enriched in clone A+. Significantly, we revealed the differential expression changes of IFN system genes and immunoglobulin (Ig) genes among the survivors of three clones. Finally, myosins and Igs were identified as co-expression modules which were positively or negatively correlated to CaHV viral loads respectively. CONCLUSIONS: Our results revealed the common and distinct gene expression changes in immune and circulatory system in the survivors of three gibel carp gynogenetic clones with different CaHV resistances. The current study represents a paradigm of differential innate and adaptive immune reactions in teleost, and will be beneficial to the disease-resistance breeding of gibel carp.

Divergent Expression Patterns and Function of Two cxcr4 Paralogs in Hermaphroditic Epinephelus coioides.

Chemokine receptor Cxcr4 evolved two paralogs in the teleost lineage. However, cxcr4a and cxcr4b have been characterized only in a few species. In this study, we identified two cxcr4 paralogs from the orange-spotted grouper, Epinephelus coioides. The phylogenetic relationship and gene structure and synteny suggest that the duplicated cxcr4a/b should result from the teleost-specific genome duplication (Ts3R). The teleost cxcr4 gene clusters in two paralogous chromosomes exhibit a complementary gene loss/retention pattern. Ec_cxcr4a and Ec_cxcr4b show differential and biased expression patterns in grouper adult tissue, gonads, and embryos at different stages. During embryogenesis, Ec_cxcr4a/b are abundantly transcribed from the neurula stage and mainly expressed in the neural plate and sensory organs, indicating their roles in neurogenesis. Ec_Cxcr4a and Ec_Cxcr4b possess different chemotactic migratory abilities from the human SDF-1α, Ec_Cxcl12a, and Ec_Cxcl12b. Moreover, we uncovered the N-terminus and TM5 domain as the key elements for specific ligand⁻receptor recognition of Ec_Cxcr4a-Ec_Cxcl12b and Ec_Cxcr4b-Ec_Cxcl12a. Based on the biased and divergent expression patterns of Eccxcr4a/b, and specific ligand⁻receptor recognition of Ec_Cxcl12a/b⁻Ec_Cxcr4b/a, the current study provides a paradigm of sub-functionalization of two teleost paralogs after Ts3R.

Divergent Expression Patterns and Function Implications of Four nanos Genes in a Hermaphroditic Fish, Epinephelus coioides.

Multiple nanos genes have been characterized in several fishes, but the functional implications of their various expression patterns remain unclear. In this study, we identified and characterized four nanos genes from a hermaphroditic fish orange-spotted grouper, Epinephelus coioides. Ecnanos1a and Ecnanos1b show divergent expression patterns, and the dynamic expression change of Ecnanos1a in pituitaries during sex change is associated with testis differentiation and spermatogenesis. Ecnanos2 and Ecnanos3 might be germline stem cells (GSCs) and primordial germ cells (PGCs)-specific markers, respectively. Significantly, Ecnanos3 3'-untranslated region (UTR) is necessary for PGC specific expression, where a non-canonical "GCACGTTT" sequence is required for miR-430-mediated repression of Ecnanos3 RNA. Furthermore, grouper Dead end (Dnd) can relieve miR-430 repression in PGCs by associating with a 23 bp U-rich region (URR) in Ecnanos3 3'-UTR. The current study revealed the functional association of multiple nanos genes with PGC formation and germ cell development in orange-spotted grouper, and opened up new possibilities for developing biotechnologies through utilizing the associations between Ecnanos3 and PGCs or between Ecnanos2 and GSCs in the hermaphroditic fish.

Comparative genome anatomy reveals evolutionary insights into a unique amphitriploid fish.

Triploids are rare in nature because of difficulties in meiotic and gametogenic processes, especially in vertebrates. The Carassius complex of cyprinid teleosts contains sexual tetraploid crucian carp/goldfish (C. auratus) and unisexual hexaploid gibel carp/Prussian carp (C. gibelio) lineages, providing a valuable model for studying the evolution and maintenance mechanism of unisexual polyploids in vertebrates. Here we sequence the genomes of the two species and assemble their haplotypes, which contain two subgenomes (A and B), to the chromosome level. Sequencing coverage analysis reveals that C. gibelio is an amphitriploid (AAABBB) with two triploid sets of chromosomes; each set is derived from a different ancestor. Resequencing data from different strains of C. gibelio show that unisexual reproduction has been maintained for over 0.82 million years. Comparative genomics show intensive expansion and alterations of meiotic cell cycle-related genes and an oocyte-specific histone variant. Cytological assays indicate that C. gibelio produces unreduced oocytes by an alternative ameiotic pathway; however, sporadic homologous recombination and a high rate of gene conversion also exist in C. gibelio. These genomic changes might have facilitated purging deleterious mutations and maintaining genome stability in this unisexual amphitriploid fish. Overall, the current results provide novel insights into the evolutionary mechanisms of the reproductive success in unisexual polyploid vertebrates.

Identification and functional characterization of three irf7 transcript variants in obscure puffer (Takifugu obscurus).

Interferon regulatory factor 7 (IRF7) is a key mediator in regulating the type Ι IFN response. Although irf7 has been identified in more than twenty fish species, alternative splicing has not been found in teleost irf7. Alternative splicing is an important mechanism expanding the transcriptomic and proteomic diversity, and has been found in several IRF family members. Here, three alternative splicing variants of irf7 were identified and characterized in obscure puffer. The first splicing transcript (Toirf7v1) was predicted to encode 428 amino acids with a DNA-binding domain (DBD), an interaction-associated domain (IAD) and a serine-rich domain (SRD). Toirf7v2 encoded 430 amino acids caused by the intron retention, and contained the whole conserved domains. Toirf7v3 encoded a truncated protein with 337 amino acids resulting from the alternative 5' splice-site selection, and lacked part of IAD domain and the entire SRD domain. Functional studies demonstrated that all of the three isoforms could activate the expression of type I IFN and IFN-stimulated genes (ISGs). Nevertheless, the two variants (Toirf7v2 and Toirf7v3) exhibited much less ability to induce transcription of IFN and ISGs compared to the Toirf7v1. Our findings suggest that these splicing variants may have distinct roles in the regulation of immune response. These results will be beneficial to understand the functional characteristics of irf7 variants in fish.

Transcriptome profiling revealed the growth superiority of hybrid pufferfish derived from Takifugu obscurus ♀ × Takifugu rubripes ♂.

Hybridization is an efficient method to breed new strains of aquatic animals. In the present study, we produced a hybrid puffer by crossing female obscure puffer with male tiger puffer. The hybrid puffer could live in fresh water like obscure puffer and exhibited growth superiority. The averaged body weight of 4- and 6-month-old hybrid puffer were respectively 38.06% and 38.93% higher than that of obscure puffer. Then, we analyzed the underlying genetic basis for the growth advantage of hybrid puffer by comparative transcriptome analysis. A total number of 4264 and 1285 differentially expressed genes (DEGs) were respectively identified from pituitary and liver transcriptome profiles between hybrid puffer and obscure puffer. Comprehensive analysis showed that the DEGs related with cell proliferation and differentiation, and protein synthesis and export, specifically showed higher expression levels in hybrid puffer, such as "ECM-receptor interaction", "focal adhesion", "protein export" and "protein processing in endoplasmic reticulum". While the DEGs involved in gametogenesis and carbohydrate and energy metabolism highly expressed in obscure puffer, such as "oxidative phosphorylation", "citrate cycle", "progesterone-mediated oocyte maturation" and "oocyte meiosis". Furthermore, a series of candidate genes related to the growth superiority of hybrid puffer were identified, such as fn1a, ptprc, plcg2, igf1, tgfß1, bmp4, abl1, col1a2, col1a1a, and myl9a. These results will be beneficial to understand the molecular basis of growth superiority and helpful to the hybrid breeding of pufferfish.

Colonic perforation in a nasopharyngeal carcinoma patient treated with fluorouracil: A case report.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a commonly encountered type of tumor. Fluorouracil (FU) is an effective treatment providing satisfactory oncologic outcomes in nasopharyngeal carcinoma patients. We describe a unique case of colonic perforation in an NPC patient treated with FU. Thus far, only two cases of intestinal perforation associated with FU treatment have been reported. We hope that the analysis of the relationship between the adverse effects of FU and physiological factors will help to reduce the incidence of colonic perforation in patients with nasopharyngeal carcinoma treated with FU. CASE SUMMARY: A 67-year-old female patient suffered from NPC stage pT3N2M0. She had a history of three surgical procedures: Partial enterectomy, partial sigmoidectomy, and sigmoidostomy. After the administration of 2.75 g FU, a bloody stool appeared and the patient developed abdominal pain. Subsequent examination indicated colitis and intestinal perforation. CONCLUSION: FU is a commonly used drug in NPC chemotherapy. The most common adverse effect of FU is gastrointestinal reaction, and the colonic perforation found here is thought to be caused by gastrointestinal mucosal injury consequential to the FU treatment. When selecting chemotherapy drugs, their side effects and the physical condition of patients should be considered, particularly in patients with a history of gastrointestinal surgery.

Dynamic and Differential Expression of Duplicated Cxcr4/Cxcl12 Genes Facilitates Antiviral Response in Hexaploid Gibel Carp.

Chemokine receptor cxcr4 and its ligand cxcl12 have evolved two paralogs in the teleost lineage. In this study, we have identified four duplicated cxcr4 and cxcl12 genes from hexaploid gibel carp, Carassius gibelio, respectively. Cgcxcr4bs and Cgcxcl12as were dynamically and differentially expressed in immune-related tissues, and significantly up-regulated in head kidney and spleen after crucian carp herpesvirus (CaHV) infection. Blocking Cxcr4/Cxcl12 axis by injecting AMD3100 brought more severe bleeding symptom and lower survival rate in CaHV-infected fish. AMD3100 treatment also suppressed the up-regulation of key antiviral genes in head kidney and spleen, and resulted in more acute replication of CaHV in vivo. Consistently, the similar suppression of up-regulated expression of key antiviral genes were also observed in CAB cells treated by AMD3100 after poly(I:C) stimulation. Finally, MAPK3 and JAK/STAT were identified as the possible pathways that CgCxcr4s and CgCxcl12s participate in to promote the antiviral response in vitro.

Development and interpretation of a pathomics-based model for the prediction of microsatellite instability in Colorectal Cancer.

Microsatellite instability (MSI) has been approved as a pan-cancer biomarker for immune checkpoint blockade (ICB) therapy. However, current MSI identification methods are not available for all patients. We proposed an ensemble multiple instance deep learning model to predict microsatellite status based on histopathology images, and interpreted the pathomics-based model with multi-omics correlation. Methods: Two cohorts of patients were collected, including 429 from The Cancer Genome Atlas (TCGA-COAD) and 785 from an Asian colorectal cancer (CRC) cohort (Asian-CRC). We established the pathomics model, named Ensembled Patch Likelihood Aggregation (EPLA), based on two consecutive stages: patch-level prediction and WSI-level prediction. The initial model was developed and validated in TCGA-COAD, and then generalized in Asian-CRC through transfer learning. The pathological signatures extracted from the model were analyzed with genomic and transcriptomic profiles for model interpretation. Results: The EPLA model achieved an area-under-the-curve (AUC) of 0.8848 (95% CI: 0.8185-0.9512) in the TCGA-COAD test set and an AUC of 0.8504 (95% CI: 0.7591-0.9323) in the external validation set Asian-CRC after transfer learning. Notably, EPLA captured the relationship between pathological phenotype of poor differentiation and MSI (P < 0.001). Furthermore, the five pathological imaging signatures identified from the EPLA model were associated with mutation burden and DNA damage repair related genotype in the genomic profiles, and antitumor immunity activated pathway in the transcriptomic profiles. Conclusions: Our pathomics-based deep learning model can effectively predict MSI from histopathology images and is transferable to a new patient cohort. The interpretability of our model by association with pathological, genomic and transcriptomic phenotypes lays the foundation for prospective clinical trials of the application of this artificial intelligence (AI) platform in ICB therapy.

Hyperbeanols F-Q, diverse monoterpenoid polyprenylated acylphloroglucinols from the flowers of Hypericum beanii.

Hyperbeanols F-Q, which are twelve undescribed monoterpenoid polyprenylated acylphloroglucinols, and four known analogues were isolated from the dried flowers of Hypericum beanii. Their structures were elucidated by detailed HRESIMS and 1D and 2D NMR data analyses. The absolute configurations of hyperbeanols FH were established by the circular dichroism (CD) exciton chirality method. The plausible biosynthetic pathway speculation of hyperbeanols F-Q indicated that diverse reactions, including prenylation, 1,6-ene reaction, rearrangement, epoxidation and dehydration, contributed to their diverse skeletons. Hyperbeanols FI, O and hypercalin B exhibited moderate nitric oxide (NO) inhibitory activities in LPS-induced RAW 264.7 macrophages, with IC50 values in the range of 17.11-28.74 µM.

Hyperberins A and B, Type B Polycyclic Polyprenylated Acylphloroglucinols with Bicyclo[5.3.1]hendecane Core from Hypericum beanii.

The first examples of type B polycyclic polyprenylated acylphloroglucinols with a bicyclo[5.3.1]hendecane core, hyperberins A (1) and B (2), were isolated from Hypericum beanii, together with three biosynthetic congeners. Their structures were established by a combination of NMR, electric circular dichroism (ECD), and X-ray diffraction analyses. These isolates indicated divergent cationic cyclization as key steps in the biosynthesis of PPAPs with diverse architectures. Compounds 1 and 2 were moderately cytotoxic and exhibited significant anti-inflammatory activities.

Differential expression and functional diversification of diverse immunoglobulin domain-containing protein (DICP) family in three gynogenetic clones of gibel carp.

Diverse immunoglobulin (Ig) domain-containing protein (DICP) family is a novel bony fish-specific multi-gene family encoding diversified immune receptors. However, their function and the implication of binding partners remain unknown. In this study, we first identified 28 DICPs from three gibel carp gynogenetic clones and revealed their high variability and clone-specific feature. After crucian carp herpesvirus (CaHV) infection, these DICPs were significantly upregulated in head kidney, kidney and spleen. The up-regulation folds in clone A+, F and H were related to the susceptibility to CaHV, progressively increasing from resistant clone to susceptible clone. Overexpression of gibel carp DICPs inhibited interferon (IFN) and viperin promoter-driven luciferase activity. The additions of E. coli extracts and lipid A significantly enhanced the inhibition effect. In addition, gibel carp DICPs can interact with SHP-1 and SHP-2. These findings suggest that gible carp DICPs, as inhibitory receptors, might specifically recognize lipid A, and then interact with SHP-1 and SHP-2 to inhibit the induction of IFN and ISGs.

Complete mitochondrial genome of Pseudoperonospora cubensis.

Pseudoperonospora cubensis is a species of water mould known for causing downy mildew on cucurbits. 454 GS FLX Titanium sequencing data was used to obtain its complete mitochondrial genome (38 553 bp). The mitogenome contains 60 genes, including two ribosomal RNA, 25 transfer RNA, 15 ribosomal proteins, five open reading frames (ORFs). The rps3 and rpl16 overlapped each other by 14 bp. The gene order and composition of P. cubensis was similar to that of most other oomycetes, and its GC content was 22.4%. It is the first report of the complete mitochondrial genome in the genus Pseudoperonospora. Phylogeny analysis indicates that P. cubensis has a close genetic relationship with genus Phytophthora.

[Characterization of Cr Tolerance and Accumulation in Lolium perenne L. and Pharibitis purpurea(L.) Voigt].

Considering the serious pollution of heavy metal-chromium (Cr) in soil, there is an urgent need for effective selection of Cr-tolerant plant species. In order to gain fundamental insights into the tolerance and accumulation capabilities of Lolium perenne L. and Pharibitis purpurea(L.) Voigt under Cr stress, a pot experiment was conducted to investigate their growth, physiology and accumulation characteristics under Cr(Ⅲ) and Cr(Ⅵ) stress. The results showed the growth parameters could intuitively reflect the toxicity levels of Cr for plants. For instance, a low-level Cr(Ⅲ) (<250 mg·kg-1) in soil was good for plant growth as indicated by the significant elevation of plant height, root length and biomass in L. perenne (P<0.05). However, Cr(Ⅵ) at all concentrations (≥25 mg·kg-1) in the soil inhibited the growth of both plant species, and the root length was particularly sensitive to the toxicity of Cr. The physiological parameters of plant represented both the toxicity of Cr and the tolerance of plants under Cr stress. A decrease of root activity and an increase of malonaldehyde content were observed under Cr stress, which indicated the physiological metabolism of plants was disturbed. In the presence of both Cr species, the proline content increased, which served as an indicator for both high Cr toxicity and increase of osmotic balance in plants. A rise in SOD and POD activity reflected the defense ability of plants against oxidative stress caused by Cr. In addition, the Cr-accumulation related parameters were the major standards for tolerant species selection. The Cr(Ⅵ) accumulation capacities of both plant species were greater than their Cr(Ⅲ) accumulation capacities. The maximum accumulation amounts of L. perenne and P. purpurea reached 957.4 mg·kg-1 and 743.3 mg·kg-1 in roots and 394.7 mg·kg-1 and 340.4 mg·kg-1 in shoots, respectively. In comparison with P. purpurea, L. perenne displayed a stronger Cr accumulation capacity in roots with a maximum bioaccumulation factor of 15.55. However, the transport ability of P. purpurea was superior to L. perenne. All of the parameters demonstrated that both L. perenne and P. purpurea could be used as alternative plants for phytoremediation of Cr-contaminated soil.

Gene expression profile of degenerated cervical intervertebral disc tissues in rats.

OBJECTIVE: To analyze the gene expression profile of degenerated cervical intervertebral disc of Sprague Dawley rats on a large scale. METHODS: Degenerated models of Sprague Dawley rats of 9 months old (degeneration group, n=9) and normal Sprague Dawley rats of 3 months old (control group, n=9) were prepared, respectively. mRNA was obtained from the cervical intervertebral disc of rats in both groups, respectively, and then labelled by Cy5 and Cy3 fluorescence respectively after reverse transcription to obtain intervertebral disc cDNA probes. cDNA probes were hybridized with BiostarR-40s gene expression profile chips and scanned by laser scanner. The results were treated with portrait analysis, standardization management, and ratio analysis with softwares. RESULTS: Compared with the rats in the control group, 9.6% (381 pieces in total) gene expression changed obviously in the rats in the degeneration group, among which, the gene expression quantities of 171 pieces increased significantly (r=the ratio of the degeneration group to the control group>2.0), 52 pieces of which had certain function. While the gene expression quantities of 211 pieces decreased significantly (r<0.5), 41 pieces of which had certain function. CONCLUSIONS: Gene chip technology can be used to analyze the gene expression profile of degenerated intervertebral disc of rats in parallel, in quantity and on a large scale, which helps to testify the representative genes and protein expression, and plays an important role in clarifying the pathogenesis of degenerated intervertebral disc.

Optimization of hollow waveguides as absorption cells for spectroscopic gas sensing.

Flexible and low-loss hollow waveguide has many advantages as an absorption cell for spectroscopic gas sensing. The characteristics of the sensing system are dependent on the parameters of the hollow waveguide cell. In this paper, a mathematical model was proposed to analyze the waveguide cell by considering waveguide loss, effective optical path length, and signal-to-noise ratio of the system. Simulation results show that the gas absorption intensity and system sensitivity are dependent not only on the waveguide length but also on the bore-diameter, signal-to-noise ratio, and the concentration of the target gases. The results provide optimizing methods for the sensing system and algorithms for error compensation. Preliminary experiments on concentration detection of methane gas were carried out and measured data showed good agreements with the simulation results.