Translating N‐Glycan Analytical Applications into Clinical Strategies for Ovarian Cancer

Protein glycosylation, particularly N‐linked glycosylation, is a complex posttranslational modification (PTM), which plays an important role in protein folding and conformation, regulating protein stability and activity, cell–cell interaction, and cell signaling pathways. This review focuses on analytical techniques, primarily MS‐based techniques, to qualitatively and quantitatively assess N‐glycosylation while successfully characterizing compositional, structural, and linkage features with high specificity and sensitivity. The analytical techniques explored in this review include LC–ESI–MS/MS and MALDI time‐of‐flight MS (MALDI‐TOF‐MS), which have been used to analyze clinical samples, such as serum, plasma, ascites, and tissue. Targeting the aberrant N‐glycosylation patterns observed in MALDI–MS imaging (MSI) offers a platform to visualize N‐glycans in tissue‐specific regions. The studies on the intra‐patient (i.e., a comparison of tissue‐specific regions from the same patient) and inter‐patient (i.e., a comparison of tissue‐specific regions between different patients) variation of early‐ and late‐stage ovarian cancer (OC) patients identify specific N‐glycan differences that improve understanding of the tumor microenvironment and potentially improve therapeutic strategies for the clinic.     

Non-additive voltammetric currents from multicomponent systems of redox-active substances

Mixtures of two redox-active compounds with dissimilar diffusion coefficients produce non-additive mass-transfer limited currents. Similarly, in the potential range where three redox-active species, decamethylferrocene (dMeFc), ferrocene (Fc) and N-methylphenothiazine (MePTZ), are oxidized simultaneously with rates controlled by linear diffusion, electrogenerated radicals diffusing outwards from the electrode react with original species diffusing towards the electrode from the bulk; thus, Fc⁺ reacts with dMeFc producing Fc and dMeFc⁺, while MePTZ⁺ reacts with both Fc and dMeFc producing MePTZ together with Fc⁺ and dMeFc⁺. These processes replace the flux of dMeFc with Fc at the second current plateau (referring to normal pulse voltammetry), and the fluxes of both dMeFc and Fc with MePTZ at the third plateau. Analogous results have been obtained and analyzed with two other multicomponent systems undergoing multiple sequential electron transfers, namely dMeFc/Fc/TPTA and dMeFc/TTF (TPTA: tri-N-p-tolylamine; TTF: tetrathiafulvalene). Since the diffusion coefficients of the three species are different, the mass-transfer limited currents of the second and third oxidation waves are not equal to the sum of the currents that each component would have produced if it were in the solution alone. Numerical simulations of the experimental voltammograms using diffusion coefficients measured independently support this mechanism. Multicomponent systems are encountered frequently in practice and our results identify one significant (∼10%) source of error in quantitative voltammetric analysis. Ways around the problem are summarized in the conclusions section.     

新型UV有色涂料用引发剂体系的研究

将热引发剂引入UV涂料参与引发，研究了单-UV引发体系的引发特点和效率，热引发剂和UV引发剂复合引发体系的引发效率，以及混合引发体系各组分的最佳比例。研究表明，在UV环氧丙烯酸树脂体系中，热引发剂能够有效地部分替代昂贵的uV引发剂，并且“热-UV”复合引发体系能使涂料固化得更完全。     

Removal of Co, Cs, and Zr radioisotopes from aqueous solutions using cellulose iminodiacetic acid chelating cum cation-exchanger

The iminodiacetic acid group containing resin acts as a chelating ion exchanger as well as a weakly acidic cation exchanger, depending upon the species present in the solution. Iminodiacetic acid group has been incorporated onto cellulose by a modified Porath's method of functionalization of polysaccharides. The resin has been used for removal of ⁵⁸Co, ¹³⁴Cs, and ⁹⁵Zr radioisotopes from their separate aqueous solutions. ⁹⁵Zr as [Zr(OH)₂(H₂O)₄]⁸⁺ tetrameric species is adsorbed from the aqueous solution at low pH through cation exchange cum chelate formation. ⁵⁸Co as Co²⁺ is complexed with the resin. ¹³⁴Cs as Cs⁺ is exchanged with equivalent amount of H⁺ ions. Cs⁺ was eluted from resin using 0.3N HCl, Co²⁺ with 4N HCl and Zr(IV) with 5N HCl. Final disposal of the resin can be done by encapsulation in the cement concrete.     

Drawing of nylon-6 by the novel incremental drawing process

Multifilament nylon-6 fibers are drawn by the novel incremental drawing process as well as by the conventional drawing process. In this process the fibers are stretched in 36 stages along the surface of two corotating cones fitted on the incremental drawing machine. Fibers are obtained from each stage, and from their diameter measurements it is shown that they are stretched in a predicted manner. Mechanical properties, as measured by Instron and by a sonic modulus tester, show higher tenacity and modulus values for the incremental process than for the conventional one at equivalent draw ratios. Structural properties are analyzed by density measurements, wide angle X-ray diffraction and birefringence. These showed higher crystallinity and higher crystalline as well as amorphous orientation factors for the incremental process at equivalent draw ratios. The mechanical property results are explained on the basis of structural development during drawing. It has been shown that the incremental drawing process is a suitable technique for obtaining superior properties in fibers and has commercial potential.     

Thermal behavior of some homogeneously polymethyl methacrylate (PMMA)‐grafted high α‐cellulose products

The graft copolymerization of methyl methacrylate (MMA) onto high α‐cellulose was carried out homogeneously in an N,N‐dimethyl acetamide/lithium chloride solvent system by using benzoyl peroxide as radical initiator. The rate of grafting was evaluated as a function of concentrations of initiator and monomer, reaction time, and temperature. The grafted products were characterized with the help of infrared spectroscopy, whereas the thermal decomposition of optimum PMMA‐grafted high α‐cellulose was studied using TGA, DTG, and DTA techniques at two heating rates, 10 and 20°C/min, in nitrogen atmosphere in the range of room temperature to 650°C. Three major decomposition steps were identified and the relative thermal stabilities of the PMMA‐grafted high α‐cellulose products were assessed. The kinetic parameters for the three decomposition steps were estimated with the help of two well‐known methods. The thermal stability of the grafted products decreased with the increase of graft yield (GY). Crystallinity or peak intensity of wide‐angle X‐ray diffraction patterns decreased with the increase of GY. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3471–3478, 2004     

Bilayered nano-hetero-structured n/n junction thin-film electrodes,WO3/Yb-Mo-BiVO4, for efficient photoelectrochemical water splitting

Journal of Applied Electrochemistry - Significant advancement in photoelectrochemical water splitting current is observed using uniquely evolved n/n junction bilayered nano-hetero-structured thin...     

Hydrogen Plasma Processing of Iron Ore

Iron is currently produced by carbothermic reduction of oxide ores. This is a multiple-stage process that requires large-scale equipment and high capital investment, and produces large amounts of CO₂. An alternative to carbothermic reduction is reduction using a hydrogen plasma, which comprises vibrationally excited molecular, atomic, and ionic states of hydrogen, all of which can reduce iron oxides, even at low temperatures. Besides the thermodynamic and kinetic advantages of a hydrogen plasma, the byproduct of the reaction is water, which does not pose any environmental problems. A review of the theory and practice of iron ore reduction using a hydrogen plasma is presented. The thermodynamic and kinetic aspects are considered, with molecular, atomic and ionic hydrogen considered separately. The importance of vibrationally excited hydrogen molecules in overcoming the activation energy barriers, and in transferring energy to the iron oxide, is emphasized. Both thermal and nonthermal plasmas are considered. The thermophysical properties of hydrogen and argon–hydrogen plasmas are discussed, and their influence on the constriction and flow in the of arc plasmas is considered. The published R&D on hydrogen plasma reduction of iron oxide is reviewed, with both the reduction of molten iron ore and in-flight reduction of iron ore particles being considered. Finally, the technical and economic feasibility of the process are discussed. It is shown that hydrogen plasma processing requires less energy than carbothermic reduction, mainly because pelletization, sintering, and cokemaking are not required. Moreover, the formation of the greenhouse gas CO₂ as a byproduct is avoided. In-flight reduction has the potential for a throughput at least equivalent to the blast furnace process. It is concluded that hydrogen plasma reduction of iron ore is a potentially attractive alternative to standard methods.     

LIQUID MEMBRANE TRANSPORT OF CEPHALOSPORIN ANTIBIOTICS: EFFECT OF SOLUTE CHEMICAL NATURE ON CARRIER SPECIFICITY

Cephalosporin antibiotics were transported from a dilute aqueous solution (feed phase) through a bulk liquid membrane containing Aliquat-336 as an anion exchange carrier in n-butyl acetate as the solvent to another aqueous solution (receiving phase) of lower pH. Under appreciable pH gradient of the feed and receiving phases, facilitated uphill transport could be obtained. Under the optimal pH condition, the intial solute flux across the bulk liquid membrane could be correlated well with the hydrophobicity of the solutes. A linear correlation exists between the initial solute flux and hydrophobicity, indicating that the solute of higher hydrophobic nature are transported at a higher rate in the bulk liquid membrane involving the specific carrier. The correlation appears to be derived from a linear dependenc of solute hydrophobicity on equilibrium constant of the reactive extraction system being exploited in the bulk liquid membrane.     

Laser Processing on CVD-Processed Alumina-Coated Carbide Inserts

Laser shock processing (LSP) has been applied to locally relieve the deleterious tensile residual stresses on the wear area of a coated tool. LSP utilizes a very short laser pulse with high energy density, which induces high-pressure stress wave propagation. The residual stresses are relieved by incident shock waves on the coating surface. Residual stress levels of LSP CVD alumina-coated carbide insert were evaluated by the x-ray diffractometer. Based on these results, LSP parameters such as number of laser pulses and laser energy density can be controlled to reduce residual stress. From the relationship between LSP parameters and the residual stress behavior, the empirical equation is derived. Crater wear on the coated carbide inserts with various LSP conditions was examined after the turning tests. We have analyzed the preliminary results to verify the effects of residual stress in reducing crater wear.