Vibration analysis for Bearing outer race condition diagnostics

This paper investigates defect detection methodologies for rolling element bearings through vibration analysis. Specifically, the utility of a new signal processing scheme combining the High Frequency Resonance Technique (HFRT) and Adaptive Line Enhancer (ALE) is investigated. The accelerometer is used to acquire data for this analysis, and experimental results have been obtained for outer race defects. Results show the potential effectiveness of the signal processing technique to determine both the severity and location of a defect. The HFRT utilizes the fact that much of the energy resulting from a defect impact manifests itself in the higher resonant frequencies of a system. Demodulation of these frequency bands through use of the envelope technique is then employed to gain further insight into the nature of the defect while further increasing the signal to noise ratio. If periodic, the defect frequency is then present in the spectra of the enveloped signal. The ALE is used to enhance the envelope spectrum by reducing the broadband noise. It provides an enhanced envelope spectrum with clear peaks at the harmonics of a characteristic defect frequency. It is implemented by using a delayed version of the signal and the signal itself to decorrelate the wideband noise. This noise is then rejected by the adaptive filter that is based upon the periodic information in the signal. Results have been obtained for outer race defects. They show the effectiveness of the methodology to determine both the severity and location of a defect. In two instances, a linear relationship between signal characteristics and defect size is indicated.

Effects of estradiol benzoate on 5'-iodothyronine deiodinase activities in female rat anterior pituitary gland, liver and thyroid gland

There is little information on the possible effects of estrogen on the activity of 5'-deiodinase (5'-ID), an enzyme responsible for the generation of T3, the biologically active thyroid hormone. In the present study, anterior pituitary sonicates or hepatic and thyroid microsomes from ovariectomized (OVX) rats treated or not with estradiol benzoate (EB, 0.7 or 14 µg/100 g body weight, sc, for 10 days) were assayed for type I 5'-ID (5'-ID-I) and type II 5'-ID (5'-ID-II, only in pituitary) activities. The 5'-ID activity was evaluated by the release of 125I from deiodinated 125I rT3, using specific assay conditions for type I or type II. Serum TSH and free T3 and free T4 were measured by radioimmunoassay. OVX alone induced a reduction in pituitary 5'-ID-I (control = 723.7 ± 67.9 vs OVX = 413.9 ± 26.9; P<0.05), while the EB-treated OVX group showed activity similar to that of the normal group. Thyroid 5'-ID-I showed the same pattern of changes, but these changes were not statistically significant. Pituitary and hepatic 5'-ID-II did not show major alterations. The treatment with the higher EB dose (14 µg), contrary to the results obtained with the lower dose, had no effect on the reduced pituitary 5'-ID-I of OVX rats. However, it induced an important increment of 5'-ID-I in the thyroid gland (0.8 times higher than that of the normal group: control = 131.9 ± 23.7 vs ovx + EB 14 µg = 248.0 ± 31.2; P<0.05), which is associated with increased serum TSH (0.6-fold vs OVX, P<0.05) but normal serum free T3 and free T4. The data suggest that estrogen is a physiological stimulator of anterior pituitary 5'-ID-I and a potent stimulator of the thyroid enzyme when employed at high doses

Solubilization of Na,K-ATPase from rabbit kidney outer medulla using only C12E8

SDS, C12E8, CHAPS or CHAPSO or a combination of two of these detergents is generally used for the solubilization of Na,K-ATPase and other ATPases. Our method using only C12E8 has the advantage of considerable reduction of the time for enzyme purification, with rapid solubilization and purification in a single chromatographic step. Na,K-ATPase-rich membrane fragments of rabbit kidney outer medulla were obtained without adding SDS. Optimum conditions for solubilization were obtained at 4ºC after rapid mixing of 1 mg of membrane Na,K-ATPase with 1 mg of C12E8/ml, yielding 98% recovery of the activity. The solubilized enzyme was purified by gel filtration on a Sepharose 6B column at 4ºC. Non-denaturing PAGE revealed a single protein band with phosphomonohydrolase activity. The molecular mass of the purified enzyme estimated by gel filtration chromatography was 320 kDa. The optimum apparent pH obtained for the purified enzyme was 7.5 for both PNPP and ATP. The dependence of ATPase activity on ATP concentration showed high (K0.5 = 4.0 µM) and low (K0.5 = 1.4 mM) affinity sites for ATP, with negative cooperativity. Ouabain (5 mM), oligomycin (1 µg/ml) and sodium vanadate (3 µM) inhibited the ATPase activity of C12E8-solubilized and purified Na,K-ATPase by 99, 81 and 98.5%, respectively. We have shown that Na,K-ATPase solubilized only with C12E8 can be purified and retains its activity. The activity is consistent with the form of (alphaß)2 association.

Indole ring oxidation by activated leukocytes prevents the production of hypochlorous acid

Hypochlorous acid (HOCl) released by activated leukocytes has been implicated in the tissue damage that characterizes chronic inflammatory diseases. In this investigation, 14 indole derivatives, including metabolites such as melatonin, tryptophan and indole-3-acetic acid, were screened for their ability to inhibit the generation of this endogenous oxidant by stimulated leukocytes. The release of HOCl was measured by the production of taurine-chloramine when the leukocytes (2 x 10(6) cells/mL) were incubated at 37ºC in 10 mM phosphate-buffered saline, pH 7.4, for 30 min with 5 mM taurine and stimulated with 100 nM phorbol-12-myristate acetate. Irrespective of the group substituted in the indole ring, all the compounds tested including indole, 2-methylindole, 3-methylindole, 2,3-dimethylindole, 2,5-dimethylindole, 2-phenylindole, 5-methoxyindole, 6-methoxyindole, 5-methoxy-2-methylindole, melatonin, tryptophan, indole-3-acetic acid, 5-methoxy-2-methyl-3-indole-acetic acid, and indomethacin (10 µM) inhibited the chlorinating activity of myeloperoxidase (MPO) in the 23-72% range. The compounds 3-methylindole and indole-3-acetic acid were chosen as representative of indole derivatives in a dose-response study using purified MPO. The IC50 obtained were 0.10 ± 0.03 and 5.0 ± 1.0 µM (N = 13), respectively. These compounds did not affect the peroxidation activity of MPO or the production of superoxide anion by stimulated leukocytes. By following the spectral change of MPO during the enzyme turnover, the inhibition of HOCl production can be explained on the basis of the accumulation of the redox form compound-II (MPO-II), which is an inactive chlorinating species. These results show that indole derivatives are effective and selective inhibitors of MPO-chlorinating activity.

In silico analysis identifies a C3HC4-RING finger domain of a putative E3 ubiquitin-protein ligase located at the C-terminus of a polyglutamine-containing protein

Almost identical polyglutamine-containing proteins with unknown structures have been found in human, mouse and rat genomes (GenBank AJ277365, AF525300, AY879229). We infer that an identical new gene (RING) finger domain of real interest is located in each C-terminal segment. A three-dimensional (3-D) model was generated by remote homology modeling and the functional implications are discussed. The model consists of 65 residues from terminal position 707 to 772 of the human protein with a total length of 796 residues. The 3-D model predicts a ubiquitin-protein ligase (E3) as a binding site for ubiquitin-conjugating enzyme (E2). Both enzymes are part of the ubiquitin pathway to label unwanted proteins for subsequent enzymatic degradation. The molecular contact specificities are suggested for both the substrate recognition and the residues at the possible E2-binding surface. The predicted structure, of a ubiquitin-protein ligase (E3, enzyme class number 6.3.2.19, CATH code 3.30.40.10.4) may contribute to explain the process of ubiquitination. The 3-D model supports the idea of a C3HC4-RING finger with a partially new pattern. The putative E2-binding site is formed by a shallow hydrophobic groove on the surface adjacent to the helix and one zinc finger (L722, C739, P740, P741, R744). Solvent-exposed hydrophobic amino acids lie around both zinc fingers (I717, L722, F738, or P765, L766, V767, V733, P734). The 3-D structure was deposited in the protein databank theoretical model repository (2B9G, RCSB Protein Data Bank, NJ).

Novel retrograde puncture method to establish preperitoneal space for laparoscopic direct inguinal hernia repair with internal ring suturing

The aim of this study was to explore the clinical efficacy of a novel retrograde puncture approach to establish a preperitoneal space for laparoscopic direct inguinal hernia repair with inguinal ring suturing. Forty-two patients who underwent laparoscopic inguinal hernia repair with retrograde puncture for preperitoneal space establishment as well as inguinal ring suturing between August 2013 and March 2014 at our hospital were enrolled. Preperitoneal space was successfully established in all patients, with a mean establishment time of 6 min. Laparoscopic repairs were successful in all patients, with a mean surgical time of 26±15.1 min. Mean postoperative hospitalization duration was 3.0±0.7 days. Two patients suffered from postoperative local hematomas, which were relieved after puncturing and drainage. Four patients had short-term local pain. There were no cases of chronic pain. Patients were followed up for 6 months to 1 year, and no recurrence was observed. Our results demonstrate that preperitoneal space established by the retrograde puncture technique can be successfully used in adult laparoscopic hernioplasty to avoid intraoperative mesh fixation, and thus reduce medical costs.