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91.
Complement pathway proteins are reported to be increased in polycystic ovary syndrome (PCOS) and may be affected by obesity and insulin resistance. To investigate this, a proteomic analysis of the complement system was undertaken, including inhibitory proteins. In this cohort study, plasma was collected from 234 women (137 with PCOS and 97 controls). SOMALogic proteomic analysis was undertaken for the following complement system proteins: C1q, C1r, C2, C3, C3a, iC3b, C3b, C3d, C3adesArg, C4, C4a, C4b, C5, C5a, C5b-6 complex, C8, properdin, factor B, factor D, factor H, factor I, mannose-binding protein C (MBL), complement decay-accelerating factor (DAF) and complement factor H-related protein 5 (CFHR5). The alternative pathway of the complement system was primarily overexpressed in PCOS, with increased C3 (p < 0.05), properdin and factor B (p < 0.01). In addition, inhibition of this pathway was also seen in PCOS, with an increase in CFHR5, factor H and factor I (p < 0.01). Downstream complement factors iC3b and C3d, associated with an enhanced B cell response, and C5a, associated with an inflammatory cytokine release, were increased (p < 0.01). Hyperandrogenemia correlated positively with properdin and iC3b, whilst insulin resistance (HOMA-IR) correlated with iC3b and factor H (p < 0.05) in PCOS. BMI correlated positively with C3d, factor B, factor D, factor I, CFHR5 and C5a (p < 0.05). This comprehensive evaluation of the complement system in PCOS revealed the upregulation of components of the complement system, which appears to be offset by the concurrent upregulation of its inhibitors, with these changes accounted for in part by BMI, hyperandrogenemia and insulin resistance.  相似文献   
92.
Tungsten heavy alloys (WHAs) are metal–metal composites consisting of nearly pure spherical tungsten particles embedded in a Ni–Fe–W or Ni–Co–W or Ni–Cu–W ductile matrix. In this dual phase alloy, there are several complicated relations between the ductile matrix and hard tungsten particles. The aim of this research was to examine the effect of varying tungsten content on the microstructure and mechanical properties of tungsten heavy alloys. The microstructural parameters (grain size, connectivity, contiguity and solid volume fraction) were measured and were found to have a significant effect on the mechanical properties of tungsten-based heavy alloys. The result shows that the binding strength between the W and the matrix phase has a major influence on the ductility of tungsten-based alloys. The larger this binding force is, the better the ductility is.  相似文献   
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Liquid–liquid dispersion and mass transfer were investigated in mechanically stirred vessels without baffles by changing operation factors such as an impeller rotation speed, off-bottom clearance, volumetric liquid ratio, etc. The dispersion regime was categorized into five groups: the sedimentary liquid was kept at the vessel bottom (I), partially elevated without any collision (II), partially dispersed by colliding with the impeller bottom (III), both liquids were partially dispersed by collisions with impeller blades (III’), and the sedimentary liquid was completely dispersed (IV). The dispersion switched to I → II → III → IV with the increasing rotation speed and decreasing off-bottom clearance. The liquid–liquid mass transfer rate was significantly enhanced with the collision of the sedimentary liquid with the impeller bottom, and subsequently increased with the increasing rotation speed, volumetric liquid ratio, and vessel diameter and with the decreasing off-bottom clearance. A multiple regression analysis method was applied to determine the mass transfer rates of III and III’.  相似文献   
96.
Polyolefin copolymers have been an important commercial product since their invention. Hence, it is crucial to study their co- and terpolymers due to their extensive use. In this paper, in situ synthesis of ethylene-propylene (EP) copolymer, its terpolymer with styrene, and composites with nickel-chromium (NiCr) layered double hydroxide (LDH) has been reported along with their thermal properties. Styrene had a significant impact on the activity, increasing the yield by 195% and 235% with an addition of 0.5 and 1.0 mL styrene, respectively, compared to neat EP. The crystallinity, melting temperature, and thermal stability decreased due to styrene; nevertheless, it performed better compared to a similar work of terpolymer where α-olefin was the third monomer. The incorporation of NiCr LDH as a drop-in filler during in situ polymerization affected adversely the thermal stability of the terpolymer. However, the ultrasonication treatment improved the thermal stability of the final product.  相似文献   
97.
Nano sized polycrystalline soft ferrite particles with composition Cu1−xCoxFe2O4 (x =0.1, 0.3, 0.5, 0.7, 0.9) were synthesized by the sol–gel technique. The existence of well-defined single cubic spinel structure was confirmed in all the samples by X-ray diffraction. The crystallite size found by XRD varied from 14.8 to 34.0 nm. The microstructure was also characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Slight expansion of the unit cell was detected with the increase of Cobalt concentration, which may be attributed due to larger ionic radius of Co2+. Lattice parameter ranged from 8.34 Å to 8.37 Å for Co2+ from 0.1–0.9. The distribution of cations amongst A- and B-sites of the lattice was estimated by X-ray diffraction by using the R-factor technique. The results showed that both Cu2+ and Co2+ ions occupy mainly the B-site while Fe3+ ions were equally distributed among A- and B-sites. The data obtained from cation distribution analysis was used to determine the magnetic moment for each sample and VSM studies were also carried out to validate these calculations. Magnetic measurements showed that the saturation magnetization (Ms) and coercivity (Hc) increased with increasing cobalt content.  相似文献   
98.
Hybrid composites from rayon fibers (~2–5 cm size) and polypropylene (PP) were fabricated by using an extruder. Fibre content of the composite was varied from 5–30% by weight and physico-mechanical properties of the composites were measured. Surface morphology as observed by SEM showed good interface adhesion between rayon and PP matrix. Furthermore inclusion of rayon (up to 15% fiber inclusion) in the composite increased tensile, bending and hardness properties. As the fiber content in the composite increased more than 15%, physico-mechanical properties decreased due to the decrease of fiber matrix adhesion. The change of tensile properties due to environmental aging was carried out by keeping the composite under soil for 1 month and tensile properties were measured periodically. The aging result suggests that composites retained about 75% of its original tensile and bending strength even after 1 month soil burial. The modified fibers were also used for the study. As such the fibers were treated with vinyl-trimethyoxysilane and methanol solution and irradiated under UV before being used with PP in extruder. The results showed retardation of the physico-mechanical properties for composites obtained from irradiated rayon fibers than the composites fabricated from non irradiated rayon fibers.  相似文献   
99.
Jute fabrics/gelatin biocomposites were fabricated using compression molding. The fiber content in the composite varied from 20–60 wt%. Composites were subjected to mechanical, thermal, water uptake and scanning electron microscopic (SEM) analysis. Composite contained 50 wt% jute showed the best mechanical properties. Tensile strength, tensile modulus, bending strength, bending modulus and impact strength of the 50% jute content composites were found to be 85 MPa, 1.25 GPa, 140 MPa and 9 GPa and 9.5 kJ/m2, respectively. Water uptake properties at room temperature were evaluated and found that the composites had lower water uptake compared to virgin matrix.  相似文献   
100.
A cloud point extraction (CPE) process using non-ionic surfactant (DC193C) to extract selected paraben compounds from water samples was investigated using reversed phase high performance liquid chromatography (RP-HPLC). The CPE process with the presence of β-cyclodextrin (βCD) functionalized ionic liquid as a modifier (CPE-DC193C-βCD-IL) is a new extraction technique that has been applied on the optimization of parameters, i.e., pH, βCD-IL concentration and phase volume ratio. This CPE-DC193C-βCD-IL method is facilitated at 30 °C, showing great losses of water content in the surfactant-rich phase, resulting in a high pre-concentration factor and high distribution coefficient. The developed method CPE-DC193C-βCD-IL did show enhanced properties compared to the CPE method without the modifier (CPE-DC193C). The developed method of CPE-DC193C-βCD-IL gives an excellent performance on the detection of parabens from water samples with the limit of detection falling in the range of 0.013–0.038 μg mL−1. Finally, the inclusion complex formation, hydrogen bonding, and π–π interaction between the βCD-IL, benzyl paraben (ArP), and DC 193C were proven using 1H NMR and 2D NOESY spectroscopy.  相似文献   
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