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Objective: To study the recovery effect of neuregulin (Nrg-1) on the sciatic nerve constriction injury as well as the expression of Nrg-1 downstream signaling molecules in sciatic nerve tissue. Methods: SD rats were selected as the experimental animals and divided into sham operation + saline intervention group (group A), sciatic nerve constriction model + saline intervention group (group B) and sciatic nerve constriction model + Nrg-1 intervention group (group C). 2 weeks, 4 weeks and 8 weeks after intervention, the sciatic nerve function parameters were detected; 8 weeks after intervention, the levels of fibrosis molecules and Nrg-1 downstream molecules in sciatic nerve tissue were determined. Results: 2 weeks, 4 weeks and 8 weeks after intervention, sciatic nerve MCV and CMAP amplitudes of group B were significantly lower than those of group A, and the sciatic nerve MCV and CMAP amplitudes of group C were significantly higher than those of group B; 8 weeks after intervention, CTGF, Col-I, Col-III, MMP2, MMP9 and PTEN levels in sciatic nerve tissue of group B were significantly higher than those of group A while ErbB, Akt and PI3K levels were significantly lower than those of group A; CTGF, Col-I, Col-III, MMP2, MMP9 and PTEN levels in sciatic nerve tissue of group C were significantly lower than those of group B while ErbB, Akt and PI3K levels were significantly higher than those of group B. Conclusion: Neuregulin can activate the PI3K/Akt to exert the recovery effect on sciatic nerve constriction injury.

The progestin receptor membrane components (Pgrmcs) contain two paralogs, Pgrmc1 and Pgrmc2. Our previous research into single knockout of Pgrmc1 or Pgrmc2 suggests that Pgrmc1 and Pgrmc2 regulate membrane progestin receptor or steroid synthesis and therefore female fertility in zebrafish. Additional roles of Pgrmcs may not be determined in using single Pgrmc knockouts due to compensatory roles between Pgrmc1 and Pgrmc2. To address this question, we crossed single knockout pgrmc1 (pgrmc1(−/−)) with pgrmc2 (pgrmc2(−/−)), and generated double knockouts for both pgrmc1 and pgrmc2 (pgrmc1/2(−/−)) in a vertebrate model, zebrafish. In addition to the delayed oocyte maturation and reduced female fertility, significant reduced ovulation was found in double knockout (pgrmc1/2(−/−)) in vivo, though not detected in either single knockout of Pgrmc (pgrmc1(−/−) or pgrmc2(−/−)). We also found significant down regulation of nuclear progestin receptor (Pgr) protein expression only in pgrmc1/2(−/−), which was most likely the cause of reduced ovulation. Lower protein expression of Pgr also resulted in reduced expression of metalloproteinase in pgrmc1/2(−/−). With this study, we have provided new evidence for the physiological functions of Pgrmcs in the regulation of female fertility by regulation of ovulation, likely via regulation of Pgr, which affects regulation of metalloproteinase expression and oocyte ovulation.

Accumulating evidence suggest that membrane progestin receptor α (mPRα) is the membrane receptor mediating nongenomic progestin signaling that induces oocyte maturation in teleost. However, the involvement of other members of mPR family in oocyte maturation is still unclear. In this study, we found impaired oocyte maturation in zebrafish lacking mPRα1, mPRα2, mPRβ, or mPRγ2. In contrast, no difference was observed in oocyte maturation in the single knockout of mPRγ1, mPRδ, or mPRε. To study possible redundant functions of different mPRs in oocyte maturation, we generated a zebrafish line lacking all seven kinds of mPRs (mprs(−/−)). We found oocyte maturation was further impaired in mprs(−/−). In addition, oocyte ovulation delay was observed in mprs(−/−) females, which was associated with low levels of nuclear progestin receptor (Pgr), a key regulator for ovulation. We also found reduced fertility in mprs(−/−) female zebrafish. Furthermore, eggs spawned by mprs(−/−) females were of poor quality.

Ovulation requires proteinases to promote the rupture of ovarian follicles. However, the identity of these proteinases remains unclear. In our previous studies using RNA-seq analysis of differential expressed genes, we found significant down-regulation of five metalloproteinases: adam8b (a disintegrin and metalloproteinase domain 8b), adamts8a (a disintegrin and metalloproteinase with thrombospondin motif 8a), adamts9, mmp2 (matrix metalloproteinase 2), and mmp9 in the nuclear progestin receptor knockout (pgr−/−) zebrafish that have failed to ovulate. We hypothesize that these metalloproteinases are responsible for ovulation and are regulated by progestin and Pgr. In this study, we first determined the expression of these five metalloproteinases and adamts1 in preovulatory follicles at different times within the spawning cycle in pgr−/− and wildtype (wt) zebrafish and under varying hormonal treatments. We found that transcripts of adam8b, adamts1, adamts9, and mmp9 increased drastically in the preovulatory follicular cells of wt female zebrafish, while changes of adamts8a and mmp2 were not significant. This increase of adam8b, adamts9, and mmp9 was significantly reduced in pgr−/−, whereas expression of adamts1 was not affected in pgr−/− zebrafish. Among upregulated metalloproteinases, adamts9 mRNA was found to be expressed specifically in follicular cells. Strong immunostaining of Adamts9 protein was observed in the follicular cells of wt fish, and this expression was reduced drastically in pgr−/−. Interestingly, about an hour prior to the increase of metalloproteinases in wt fish, both Pgr transcript and protein increased transiently in preovulatory follicular cells. The results from in vitro experiments showed that adamts9 expression markedly increased in a dose, time and Pgr-dependent manner when preovulatory follicles were exposed to a progestin, 17α,20β-dihydroxy-4-pregnen-3-one (DHP). Taken together, our results provide the first evidence that upregulation of adamts9 occurs specifically in preovulatory follicular cells of zebrafish prior to ovulation. Progestin and its receptor (Pgr) are essential for the upregulation of metalloproteinases.

Recent investigations suggest progestin receptor membrane component 1 (PGRMC1) associates with and transports a wide range of molecules such as heme, cytochromes P450, steroids with 21 carbons, membrane progestin receptor alpha (mPRα/Paqr7), epidermal growth factor receptor (EGFR), and insulin receptor. It is difficult to discriminate the true functions of PGRMC1 from the functions of its associated molecules using biochemical and pharmacological approaches. To determine the physiological function(s) of PGRMC1, we generated global knockouts for pgrmc1 (pgrmc1−/−) in zebrafish. We found a reduction in both spawning frequency and the number of embryos produced by female mutants. We also observed reduced sensitivity of fully-grown immature oocytes to a progestin hormone and a reduced number of oocytes undergone meiotic maturation both in vivo and in vitro in pgrmc1−/−. This reduced sensitivity to progestin corresponds well with significant reduced expression of mPRα, the receptor mainly responsible for mediating oocyte maturation and meiosis resumption in fish. The results provide in vivo and in vitro evidence for the physiological functions of Pgrmc1 in oocyte maturation and fertility, as well as a plausible molecular mechanism via regulation of mPRα, which in turn directly regulates oocyte maturation and affects fertility in zebrafish.

Condition assessment of cables has gained more attention for the bridge safety. The cable is under tensile load in service. The effect of tensile load for detecting broken wires on parallel wire cable based on guided waves is investigated. The sample cable with broken wires under several levels of tensile load is detected using guided waves based on the magnetostrictive effect. The amplitude of flaw echo increases monotonically with the increasing of tension. The results indicate that the tensile load brings benefit for detecting broken wires in the parallel wire cable.

microRNAs (miRNAs) are small non-coding RNAs that regulate gene expression through post-transcriptional interactions with mRNA. miRNAs have recently emerged as key regulators of various cancers. Although miR- 27a has been implicated in several other cancers, its role in hepatitis B virus-related hepatocellular carcinoma (HCC) is unknown. In this study, we showed miR-27a to be frequently up-regulated in HCC tissues and HCC cell lines (HepG2 and Huh7). Overexpression of miR-27a enhanced cell proliferation, promoted migration and invasion, and activated cell cycling in HepG2 and Huh7 cells. In summary, our results suggest that up-regulation of miR-27a may play an oncogenic role in the development of HCC and might thus be a new therapeutic target in HCC patients.

Cables are used as critical structure components for suspended and cable-stayed bridges. It has been recently increased the need for inspection methods to assess the conditions of the cables due to owners concern about the operability and safety of such aging structures. An alternative technique is being developed in this paper. The magnetostrictive guided wave technology is used to test broken wires. The suitability of this method is studied through application tests on experimental setups, lab-made cables with simulated broken wires and field test. Test Results indicate that this technique can detect two broken wires away exceeding two meters and propagating over one hundred meters. It is a promising method for nondestructive testing of bridge cables.

Prestressing strands are widely used in civil structures. The health monitoring of the strands is an important factor in evaluating the structural safety. This paper aims to improve the detection sensitivity of the guided wave technique in strands by wavelet processing. Groove defects with different depths are cut in the wire and detected by magnetostrictive sensors. The wavelet threshold method is employed to denoise the signals. In this study, the suitable thresholds are related to the median value of the coefficients. Results show that defects above 3.6% cross section loss can be found after this processing. Moreover, the amplitudes of the defect signals are related to the defect depths, which can be used to size the defects.

Corrosion of prestressing strands is a main durability issue for prestressing structures. In general, the corrosion zones of strands are hidden in structures which lead to be hardly inspected by traditional methods. An instrument for detecting the non visible corrosion of prestressing strands using magnetostrictive guided waves is provided. The instrument is described in detail. The workflow to detect the strands is provided. Field trials and laboratory experiments show that the information of position, length and amount of the corrosion can be obtained from the data. The instrument provides support for ensuring the safety of prestressing structures.

Pulsed eddy current (PEC) technique has been successfully used for measuring wall thinning of carbon steel equipments without removal of the insulation. In field applications, the probe performance decreases in presence of ferromagnetic claddings. This paper presents a method based on saturation magnetization to solve this problem. The main principle of this method is to weaken the magnetic shielding effect of the cladding by magnetizing it to saturation. A U-shaped magnetizer is designed to realize this method. Contrast experiments are performed on a Q235 steel plate covered by a galvanized steel cladding. The experiment results show that the thickness measurement range and lift-off range are increased by applying this method to the common PEC probe.

Failure of the drill pipe thread is always a very serious problem which may result in serious accidents and rework during the drilling of oil wells. Rupture crack of the drill pipe thread may result in great economic and labour losses, so they need to be inspected periodically. As the drill pipe thread is not a smooth surface and is in the end area of drill pipes, it is very difficult to be inspected by traditional Non-destructive testing (NDT) methods. According to the experiment results and the requirement of the working conditions in the field, a local MFL inspection method, which is the most adaptive inspection method, is determined. Laboratory testing and field experience show that this inspection method can detect the crack as small as 0.6mm (depth) in the thread root and thus reduces the risks of drilling failure. This local MFL inspection method can inspect flaws of the drill pipe thread that occur in practice exactly and quickly, and it has very wide application perspectives.

The adsorption orientation and adsorption characteristics of aliphatic-nonpolar amino acids represented by L-methionine on silver nanoparticles were studied by FT-surface-enhanced Raman spectroscopy (FT-SERS) method with different pH and concentrations. According to the experiments, in order to get the best FT-SERS effects, the optimal concentration range of the L-methionine on silver sol is between 10(-3) mol x L(-1)-10(-4)(mol x L(-1). The FT-SERS effects and adsorption model change with pH; The SERS are poor when pH is near the isoelectric point or over 11 or 3. The interaction of L-methionine with Ag nanoparticles is the physical and chemical adsorption by NH3, COO-, S, which could also be effected by pH. From the results and previous reports on this aspect, the general rules of the adsorption model and the orientation of the aliphatic-nonpolar amino acids on silver nanoparticles were speculated, which would be useful for the study of amino acids, protein, peptide, enzyme etc.