Methacrylic acid in situ modified steel converter slag/natural rubber composites: Resourceful utilization of steelmaking solid wastes

As a by-product of the steelmaking industry, the large-volume production and accumulation of steel converter slag cause environmental issues such as land occupation and dust pollution. Since metal salts of unsaturated carboxylic acid can be used to reinforce rubber, this study explores the innovative application of in-situ modified steel slag, mainly comprising metal oxides, with methacrylic acid (MAA) as a rubber filler partially replacing carbon black. By etching the surface of steel slag particles with MAA, their surface roughness was increased, and the chemical bonding of metal methacrylate salt was introduced to enhance their interaction with the molecular chain of natural rubber (NR). The results showed that using the steel slag filler effectively shortened the vulcanization molding cycle of NR composites. The MAA in-situ modification effectively improved the interaction between steel slag and NR molecular chains. Meanwhile, the physical and mechanical properties, fatigue properties, and dynamic mechanical properties of the experimental group with MAA in-situ modified steel slag (MAA-in-situ-m-SS) were significantly enhanced compared with those of NR composites partially filled with unmodified slag. With the dosage of 7.5 phr or 10 phr, the above properties matched or even exceeded those of NR composites purely filled with carbon black. More importantly, partially replacing carbon black with modified steel slag reduced fossil fuel consumption and greenhouse gas emission from carbon black production. This study pioneered an effective path for the resourceful utilization of steel slag and the green development of the steelmaking and rubber industries.

Synergistic Effect by Polyethylene Glycol as Interfacial Modifier in Silane-Modified Silica-Reinforced Composites

The viscoelastic behavior and reinforcement mechanism of polyethylene glycol (PEG) as an interfacial modifier in green tire tread composites were investigated in this study. The results show a clear positive effect on overall performance, and it significantly improved all the parameters of the "magic triangle" properties, the abrasion resistance, wet grip and ice traction, as well as the tire rolling resistance, simultaneously. For the preparation of the compounds, two mixing steps were used, as PEG 4000 was added on the second stage in order to avoid the competing reaction between silica/PEG and silanization. Fourier transform infrared spectroscopy (FTIR) confirmed that PEG could cover the silanol groups on the silica surface, resulting in the shortening of cure times and facilitating an increase of productivity. At low content of PEG, the strength was enhanced by the improvement of silica dispersion and the slippage of PEG chains, which are chemically and physically adsorbed on silica surface, but the use of excess PEG uncombined with silica in the compound, i.e., 5 phr, increases the possibility to shield the disulfide bonds of bis(3-(triethoxysilyl)-propyl) tetrasulfide (TESPT), and, thus, the properties were deteriorated. A constrained polymer model was proposed to explain the constrained chains of PEG in the silica-loaded composites on the basis of these results. An optimum PEG content is necessary for moderately strong matrix-filler interaction and, hence, for the enhancement in the mechanical properties.

[Blomia tropicalis is found in a flour warehouse of a food factory in a civil aviation airport]

Objective To investigate whether there is Blomia tropicalis breeding in the flour warehouse of food factory in a civil aviation airport, and, if there is, to observe the morphological structure of the mite. Methods The flour samples were collected from the flour warehouse of food factory in a civil aviation airport. The breeding mites were isolated from the samples by direct microscopy and made into specimens to observe with a light microscope. Results Female Blomia tropicalis was found in the collected flour samples. Under the microscope, the mite was nearly spherical, and it had no tergum and claw. Its apodemeⅠ was developed and connected in the midline. The reproductive hole was located between the foot Ⅲ and IV level and was covered with a pair of oblique genital folds. The foot Ⅲ and Ⅳ had no solenoids. The copulatory pouch was a long, slightly curved tube, extending from the end of the mite. ConclusionsBlomia tropicalis has been found in the flour warehouse of a food factory in the civil aviation airport. The main distinguishing feature of this mite is that it has no tergum, its feet have no pectinate inferior tarsus scales or claw, the feetⅠgenu has only one solenidia, and feet Ⅲ and Ⅳ have no solenidias.

Estimation of standard liver volume in Chinese adult living donors

AIM

To determine a formula predicting the standard liver volume based on body surface area (BSA) or body weight in Chinese adults.

MATERIALS AND METHODS

A total of 115 consecutive right-lobe living donors not including the middle hepatic vein underwent right hemi-hepatectomy. No organs were used from prisoners, and no subjects were prisoners. Donor anthropometric data including age, gender, body weight, and body height were recorded prospectively. The weights and volumes of the right lobe liver grafts were measured at the back table. Liver weights and volumes were calculated from the right lobe graft weight and volume obtained at the back table, divided by the proportion of the right lobe on computed tomography. By simple linear regression analysis and stepwise multiple linear regression analysis, we correlated calculated liver volume and body height, body weight, or body surface area.

RESULTS

The subjects had a mean age of 35.97 +/- 9.6 years, and a female-to-male ratio of 60:55. The mean volume of the right lobe was 727.47 +/- 136.17 mL, occupying 55.59% +/- 6.70% of the whole liver by computed tomography. The volume of the right lobe was 581.73 +/- 96.137 mL, and the estimated liver volume was 1053.08 +/- 167.56 mL. Females of the same body weight showed a slightly lower liver weight. By simple linear regression analysis and stepwise multiple linear regression analysis, a formula was derived based on body weight. All formulae except the Hong Kong formula overestimated liver volume compared to this formula.

CONCLUSIONS

The formula of standard liver volume, SLV (mL) = 11.508 x body weight (kg) + 334.024, may be applied to estimate liver volumes in Chinese adults.

Isothermal titration calorimetry - a new method for the quantification of microbial degradation of trace pollutants

The environmental fate and, in particular, biodegradation rates of hydrophobic organic compounds (HOC) are of high interest due to the ubiquity, persistence, and potential health effects of these compounds. HOC tend to interact with bioreactor materials and sampling devices and are frequently volatile, so that conventionally derived degradation parameters are often biased. We report on the development and validation of a novel calorimetric approach that serves to gain real time information on the kinetics and the physiology of HOC bioconversion in aqueous systems while overcoming weaknesses of conventional biodegradation experiments. Soil bacteria Mycobacterium frederiksbergense LB501T, Rhodococcus erythropolis K2-3 and Pseudomonas putida G7 were exposed to pulsed titrations of dissolved anthracene, 4-(2,4-dichlorophenoxy)butyric acid or naphthalene, respectively, and the thermal responses were monitored. The combinations of strains and pollutants were selected as examples for complete and partial biodegradation and complete degradation with storage product formation, respectively. Heat production signals were interpreted thermodynamically and in terms of Michaelis-Menten kinetics. The half-saturation constant k(D) and the degradation rate r(D)(Max) were derived. Comparison with conventional methods shows the suitability to extract kinetic degradation parameters of organic trace pollutants from simple ITC experiments, while thermodynamic interpretation provided further information about the metabolic fate of HOC compounds.

Effect of feeding allowance level on embryonic survival, IGF-1, insulin, GH, leptin and progesterone secretion in early pregnancy gilts

The present experiment was conducted to evaluate the effects of feeding allowance level on embryonic survival, uterine development and reproductive hormone secretion in early gestation gilts. A total of 54 F1 crosses of Landrace x Large white gilts were randomly allocated to three treatment groups of high (H, 2 x maintenance), medium (M, 1.2 x maintenance) and low (L, 0.6 x maintenance) feeding level after mating. Blood samples and uterine flushings were collected on day 12, 25 and 35 of pregnancy, and embryonic survival rate was estimated. Concentrations of insulin-like growth factor I (IGF)-1, insulin, growth harmone (GH), leptin and progesterone in serum and uterine flushings were determined by enzyme-linked immunosorbent assay. Embryonic survival was affected by dietary treatment; total number of viable embryos and embryo survival of group M were higher than other groups in the early pregnancy (p < 0.05). Greater foetal weight in M gilts was achieved when gestation advanced to day 35 (p < 0.05), though there was no difference on day 25 of pregnancy among treatments. No appreciable differences were observed in the crown-rump length on day 25 and 35 of pregnancy among groups. Greater weight of uterus and products of conception were identified in M gilts compared with group H and L (p = 0.024 and p = 0.005, respectively) on day 25 of pregnancy. The hormone level was greatly affected by feeding allowance level. In serum, concentrations of IGF-1, leptin and insulin tended to be greater in H than in M and L during the early gestation, while concentrations of GH were greater in M and progesterone were the lowest in H. At the same time, feed allowance level affected the concentration of IGF-1, insulin, GH, leptin and progesterone in uterine flushings. These data demonstrated that feed allowance level after mating has important consequence on embryo survival, embryo development and uterine development, possibly mediated by nutrition level inducing changes in concentrations of reproductive hormones and/or intermediary metabolites in early pregnancy.

Blood–retinal barrier disruption and ultrastructural changes in the hypoxic retina in adult rats: the beneficial effect of melatonin administration

Reactive changes in astrocytes and Müller cells in the retina of adult rats subjected to hypoxia were investigated. Along with this, the integrity of the blood-retinal barrier (BRB) was assessed using fluorescent and electron-dense tracers. In hypoxic rats, mRNA and protein expression of glial fibrillary acidic protein (GFAP) and aquaporin-4 (AQ4) were significantly increased. AQ4 immunoreactive cells were identified as astrocytes and Müller cells by double immunofluorescence labelling. Another alteration in the hypoxic retina was marked reduction in melatonin content compared to controls. In this connection, administration of exogenous melatonin reduced the tissue concentration of vascular endothelial growth factor (VEGF) and nitric oxide (NO); both were elevated in hypoxic rats. A major structural change in the hypoxic retina was swelling of astrocyte and Müller cell processes but this was noticeably attenuated after melatonin administration. Following an intraperitoneal or intravenous injection of rhodamine isothiocyanate (RhIC) or horseradish peroxidase (HRP), leakage of both tracers was observed in the retina in hypoxic rats but not in the controls, indicating that the functional integrity of the BRB is compromised in hypoxia/reoxygenation. It is suggested that enhanced tissue concentration of VEGF and NO production in the hypoxic retina contribute to increased permeability of the retinal blood vessels. The concurrent up-regulation of AQ4, a water-transporting protein, in astrocytes and Müller cells in hypoxia suggests its involvement in oedema formation. Since melatonin effectively reduced the vascular permeability in the retina of hypoxic rats, as evidenced by reduced leakage of RhIC, we suggest that its administration may be of potential benefit in the management of retinal oedema associated with retinal hypoxia.

Growth-associated gene expression profiles by microarray analysis of trophoblast of molar pregnancies and normal villi

We used microarray analysis to investigate expression profiles of 589 known genes committed to cell growth control to characterize regulatory circuitry for cell proliferation in complete moles (CMs). CMs are characterized by hyperplastic trophoblast and have a high propensity to give rise to choriocarcinoma. Characteristic alterations in gene expression profiles were observed when compared with normal villi. Fifty-seven genes were significantly up-regulated in CMs and involved the Ras-Map kinase 3, Jak-STAT5, and Wnt signal pathways, implicating growth factor or cytokine-mediated signal pathways in the trophoblastic hyperplasia of CMs. Several genes associated with anti-apoptosis, cell structuring, and/or cell attachment were also up-regulated in CMs. In contrast, relatively fewer genes were down-regulated and these involved IGFBPs, versican, interleukin-1, tumor necrosis factor receptor, CD44, and RAD52. Genes identified in this study may elucidate regulation mechanisms of trophoblastic proliferation and mechanisms causing a pathological phenotype in CMs.

In vitro development of caprine ovarian preantral follicles

The in vitro growth and developmental pattern of caprine preantral follicles cultured in agar gel was observed. Preantral follicles 50 to 150 microm in diameter were isolated from prepuberal goat ovaries by treatment with collagenase and DNase. The isolated preantral follicles were cultured in agar gel for up to 14 days. A group of 10 follicles in different developmental stages was cultured in a culture well coated with 0.6% agar gel and filled with DMEM medium supplemented with FCS (10%), hypoxanthine (2 mmol/mL), dbcAMP (2 mmol/mL), FSH (100 ng/mL), insulin-transferrin-selenium (ITS) (50 ng/mL), IGF-1 (50 ng/mL), hydrocortisone (40 ng/mL) and antibiotics. Follicle viability was determined under an inverted phase-contrast microscope according to morphological and histological criteria, and follicle growth was assessed by their size and appearance. The results showed that the three-dimensional structures and forms of follicles were basically maintained intact during culture. Primary follicles developed into secondary follicles and a few of them into antral follicles. A large portion of secondary follicles entered the antral stage, and oocytes also acquired growth. The formation of theca lamina and zona pellucida was observed. The survival capacity of secondary follicles was greater than primary follicles. The survival rates for primary and secondary follicles were 11.36% (5/44) and 71.16% (53/74), respectively. During in vitro development the follicles demonstrated dominance. This experiment revealed the preliminary characteristics of the in vitro development of caprine preantral follicles.

Nuclear-cytoplasmic interaction and development of goat embryos reconstructed by nuclear transplantation: production of goats by serially cloning embryos

The time of pronuclear formation of in vivo-matured oocytes was examined. Maturation-promoting factor (MPF) activity in enucleated and electrically activated oocytes was checked by assessment of nuclear envelope breakdown (NEBD) of fused blastomeres. The effect of stage of the cell cycle of donor cells and recipient oocytes on DNA synthesis and development of reconstructed embryos was studied. MPF activity declined rapidly to approximately 63.2% at 1 h, to 9.7% at 5 h, and to the level at which NEBD cannot occur at 7 h postactivation. All blastomeres that were fused at the time of recipient cytoplasm activation underwent NEBD and subsequent DNA synthesis. However, when blastomeres were fused to enucleated oocytes at 7 h postactivation, no NEBD was observed; DNA was replicated in nuclei at the G1/S border, but in G2 nuclei no DNA replication was observed. The proportion of development to blastocysts of reconstructed goat embryos increased with the decline in MPF activity in fused recipient cytoplasm when reconstruction took place at 0-6 h postactivation of enucleated oocytes. Generations 1, 2, 3, 4, 5, and 6 of cloned goat embryos were produced by a combination of nuclear transplantation and in vitro techniques. After transfer to recipients, 45 kids were obtained, including three pairs of monozygotic twins, three series of monozygotic triplets, two series of monozygotic quadruplets, three series of monozygotic quintuplets, and one series of monozygotic heptaplets. The present study indicates that normal DNA replication of goat blastomere nuclei can be accomplished in enucleated oocytes when MPF activity is low, regardless of the stage of the cell cycle of donor nuclei; induction of NEBD and prematuration chromosome condensation is not essential for further development of reconstructed goat embryos.

A monoclonal anti-HLA-B27 antibody which is reactive with a linear sequence of the HLA-B27 protein is useful for the study of molecular mimicry

In the search for cross-reactivity between bacteria and HLA-B27, three groups of investigators have identified several bacterial envelope proteins which are reactive with the monoclonal anti-HLA-B27 antibodies B27.M1 and B27.M2. Since these two antibodies react poorly with HLA-B27-derived synthetic peptides, it is not possible to locate the reactive epitopes on the HLA-B27 using synthetic peptides. Here, we introduce Ye-2, a monoclonal anti-HLA-B27 antibody which, unlike B27.M1 and B27.M2, is reactive with a synthetic peptide derived from residues 63-84 of HLA-B27.1. Analysis with a cross-reactive peptide derived from residues 226-244 of bovine carbonic anhydrase suggests that only a few of the amino acid residues in the HLA-B27-derived peptide are responsible for the reactivity. This antibody should be a useful adjunct in a preliminary assessment of whether a bacterial protein mimics HLA-B27 in primary structure.

An experimental mouse model of Yersinia-induced reactive arthritis

An experimental animal model of Yersinia-induced arthritis was successfully developed in mice using Yersinia enterocolitica WA. In order for the Yersinia to induce arthritis the strain had to be cured of plasmid. The arthritis-susceptible mouse strains were DBA/2 and BDF1. C57B1/6, Balb/c, CBA and DBA/1 were arthritis-resistant. Both the dose of bacteria and the route of administration were critical.

A Yersinia pseudotuberculosis protein which cross-reacts with HLA-B27

The most-debated question in the investigation of the spondyloarthropathies has been whether there is molecular mimicry between host HLA-B27 antigens and the arthritis-causing pathogens. We have generated a monoclonal anti-HLA-B27 antibody in our laboratory and have used a radioimmunoassay to screen a panel of bacterial species. Two strains of Yersinia pseudotuberculosis were found to be highly reactive. The cross-reactive Yersinia component was identified by Western blot to be a 19,000 component. A preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis chromatography apparatus was constructed to isolate milligram quantities of this component. To verify that the component carried the HLA-B27-specific epitope, rabbits were hyperimmunized with the purified materials. Affinity-purified antibodies from one of the immunized rabbits indeed carried anti-HLA-B27 activity. Last, antibodies generated against synthetic peptides derived from the HLA-B27.1 amino acid sequence were tested against the Yersinia component. Positive reactivity was found with antibodies generated against a peptide spanning residues 69-83 of the HLA-B27.1 protein. Since this resides in the segment responsible for the allotypic specificity of the antigen, these experiments establish the presence of molecular mimicry to a high degree of confidence.

A Yersinia pseudotuberculosis protein which cross-reacts with HLA-B27

The most-debated question in the investigation of the spondyloarthropathies has been whether there is molecular mimicry between host HLA-B27 antigens and the arthritis-causing pathogens. We have generated a monoclonal anti-HLA-B27 antibody in our laboratory and have used a radioimmunoassay to screen a panel of bacterial species. Two strains of Yersinia pseudotuberculosis were found to be highly reactive. The cross-reactive Yersinia component was identified by Western blot to be a 19,000 component. A preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis chromatography apparatus was constructed to isolate milligram quantities of this component. To verify that the component carried the HLA-B27-specific epitope, rabbits were hyperimmunized with the purified materials. Affinity-purified antibodies from one of the immunized rabbits indeed carried anti-HLA-B27 activity. Last, antibodies generated against synthetic peptides derived from the HLA-B27.1 amino acid sequence were tested against the Yersinia component. Positive reactivity was found with antibodies generated against a peptide spanning residues 69-83 of the HLA-B27.1 protein. Since this resides in the segment responsible for the allotypic specificity of the antigen, these experiments establish the presence of molecular mimicry to a high degree of confidence.