The influence of capital market laws and initial public offering (IPO) process on venture capital

This paper is concerned with the influence of capital market laws and initial public offering (IPO) process on venture capital. It discusses the impact of US federal state laws and Securities and Exchange Commission (SEC) regulations to the venture capital markets, arguing if the rules and regulatories are burdensome to entrepreneurs and new-growth businesses. The impact of Sarbanes-Oxley Act and the future Investment Act on venture capital funds and entrepreneurial companies going public are also discussed. The paper proposes the model of venture capital financing describing the process from fund raising to investment exits, the linkages of the venture capital market to the financial/capital markets and the related capital market laws. The policy implications on SEC regulations essential to the development of venture capital industry are suggested.     

Polymerization of n‐hexyl isocyanate with CpTiCl2(OR) (R = functional group or macromolecular chain): A route to ω‐functionalized and block copolymers and terpolymers of n‐hexyl isocyanate

Well‐defined ω‐cholesteryl poly(n‐hexyl isocyanate) (PHIC–Chol), as well as diblock copolymers of n‐hexyl isocyanate (HIC) with styrene, PS‐b‐PHIC [PS = polystyrene; PHIC = poly(n‐hexyl isocyanate)], and triblock terpolymers with styrene and isoprene, PS‐b‐PI‐b‐PHIC and PI‐b‐PS‐b‐PHIC (PI = polyisoprene), were synthesized with CpTiCl₂(OR) (R = cholesteryl group, PS, or PS‐b‐PI) complexes. The synthetic strategy involved the reaction of the precursor complex CpTiCl₃ with cholesterol or the suitable ω‐hydroxy homopolymer or block copolymer, followed by the polymerization of HIC. The ω‐hydroxy polymers were prepared by the anionic polymerization of the corresponding monomers and the reaction of the living chains with ethylene oxide. The reaction sequence was monitored by size exclusion chromatography, and the final products were characterized by size exclusion chromatography (light scattering and refractive‐index detectors), nuclear magnetic resonance spectroscopy, and, in the case of PHIC–Chol, differential scanning calorimetry. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6503–6514, 2005     

Determination of engineered nanoparticles on textiles and in textile wastewaters

Textile materials with engineered nanoparticles (ENPs) have excellent properties as they are antibacterial, antimicrobial, water resistant and protective. The textile industry has recognized the importance and the advantages of ENPs, so they comprise one of the fastest developing branches of processing.The most important sources of ENPs released to the environment from textiles are textile-industry wastewaters and waters from large hospital or hotel laundries. In addition, waste textile materials coated with ENPs present a threat to the environment, if such materials are not properly handled and disposed of after use.Currently, the toxicity and the potential harm of ENPs widely applied on textiles are not thoroughly investigated and/or eliminated. Consequently, there is an urgent need to define the most appropriate analytical methods for monitoring ENPs on textiles.This review presents the most important techniques for monitoring ENPs on textile materials and in textile-wastewater samples, from the perspective of protecting the environment and human health.     

Aqueous sec analysis of cationic polymers as gene carriers

Cationic polymers have been receiving much attention as non-viral gene vectors.The aqueous mobile phase was optimized in combination with Shodex OHpak SB columns for size-exclusion chromatography(SEC)analysis of disulfide-containing poly(ethylene imine)(PEI)derivatives used in gene delivery.Addition of acetonitrile in mobile phase was shown to be able to suppress the hydrophobic interactions between polymer analytes and the stationary phase.The absolute molecular weights and distributions of the cationic polymers were determined directly from online SEC-MALS(multi-angle light scattering)/RI(refractive index detector).The results demonstrate that a good SEC separation of disulfide-containing PEI derivatives used in gene delivery with little band broadening was achieved.     

Enhanced electrocatalytic degradation of 2,4-Dinitrophenol (2,4-DNP) in three-dimensional sono-electrochemical (3D/SEC) process equipped with Fe/SBA-15 nanocomposite particle electrodes: Degradation pathway and application for real wastewater

2,4-dinitrophenol (2,4-DNP), which is a nitrophenol compound, is a carcinogenic and non-biodegradable pollutant, which is found at high concentrations in industrial wastewater. Degradation of 2,4-DNP using a three-dimensional sono-electrochemical (3D/SEC) process equipped with G/β-PbO₂ anode and Fe/SBA-15 nanocomposite particle electrodes was evaluated in the present study. Investigating the effect of parameters including pH, electrolysis time, current density, and 2,4-DNP concentration on the performance of the 3D/SEC-Fe-SBA-15 process in 2,4-DNP degradation was considered, and optimization of these parameters was done using the Taguchi design technique. Field emission scanning electron microscopy (FESEM), X-ray diffraction analysis (XRD), energy-dispersive X-ray spectroscopy mapping (EDX-mapping), transmission electron microscopy (TEM), and Fourier Transform Infrared Spectroscopy (FTIR)) were the analyses techniques used to support the successful synthesis of Fe-SBA-15 and G/β-PbO₂ anode. The optimum values obtained for pH, electrolysis time, current density, and 2,4-DNP concentration were 5.0, 60.0 min, 5.0 mA/cm², and 50.0 mg/L, respectively. The experimental removal efficiencies of 2,4-DNP, COD, and TOC using 3D/SEC-Fe-SBA-15 process, under the mentioned conditions, were obtained to be 96.3%, 88.28%, and 83.82%, respectively. In addition, the AOS value was developed from ?0.29 to + 0.88; this indicates the high mineralization of 2,4-DNP and improvement of the solution biodegradability. Detecting the intermediates produced during the degradation process was done by LC-MS analysis, and pathways for its degradation was proposed. Results were indicative of the high potential of the 3D/SEC-Fe-SBA-15 process for treating wastewater containing phenolic compounds, e.g., 2,4-DNP, and can provide acceptable efficiency.     

Biosynthesis of Cd-bound phytochelatins by <Emphasis Type="Italic">Phaeodactylum tricornutum</Emphasis> and their speciation by size-exclusion chromatography and ion-pair chromatography coupled to ICP–MS

Cd-bound phytochelatins (Cd–PCs) have been synthesised by incubation of Phaeodactylum tricornutum cell cultures with Cd and purified by size-exclusion chromatography–UV–Vis. These complexes, which were identified in previous work, have now been used as model substances to develop and optimise ion-pair chromatography (IPC) coupled to inductively coupled plasma–mass spectrometry (ICP–MS) for analysis of Cd–PCs. Subsequent analysis of samples taken from Silene vulgaris plants cultivated under heavy metal stress conditions revealed Cd signals but no Cd–PC signals. By use of isotopically enriched ¹¹⁶Cd–PCs the sample preparation steps were verified to determine the stability of the analytes. We observed species transformation between Cd–PCs and other unidentified Cd complexes. Consequently, the kinetic and thermodynamic lability of Cd–PCs are decisive factors in their detection.     

Size and shape of Nafion particles in water after high‐temperature treatment

Perfluorosulfonic acid ionomers have been widely used as proton‐conducting materials in polymer‐electrolyte membrane fuel cells and their dispersions in polar solvents are used to prepare proton‐conducting membranes as well as catalyst layers. While it has been known that the dispersed particles become monodisperse after heating to 230 °C or above, their size and shape have not been fully characterized yet. Cryogenic transmission electron microscopy images and small‐angle X‐ray scattering profiles of the dilute aqueous dispersions before and after heating to 240 °C have clearly shown that rod‐like particles became significantly shorter cylinders without changing their radii. Particle length distributions were lognormal and average molar mass and dispersity after heating to 240 °C were consistent with the values from size exclusion chromatography. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 813–818     

Subunit structure of glycinin and its molecular species based on RP-HPLC, gel electrophoresis and SEC studies

Glycinin and its molecular species (glycinin I and glycinin II) were separated and isolated. The number and kind of subunits of glycinin, glycinin I and glycinin II were determined. Studies were carried out under different experimental conditions using slab gel electrophoresis, size-exclusion chromatography and reversed-phase high performance liquid chromatography. Gel electrophoresis was done using both continuous and discontinuous system and under varying concentrations of resolving gel. In addition, the subunits were separated by reversed phase using gradient program. Glycinin and glycinin II were found to have 12 subunits each while glycinin I showed six subunits. Molecular weight and weight ratio in each case were also determined.     

Analysis of composition complicated binary mixture by quantitative SEC

The analyses of the composition of a binary mixture composed of two kinds of industrial complicated materials have great importance for formulation in practice. The present paper provides a quantitative size exclusion chromatography (SEC) method based on the principle of absolute quantification of SEC to solve the problem. The conventional data treatment procedure for the differential refractive index (DRI) signal of SEC H(V) is improved first by dividing it with the injected sample weight and leads to a novel defined weight normalized distribution H _w(V) and its integral I _w(V). These two distributions reflect the response constant of the sample in addition to the conventional normalized distribution F(V). The difference of the average response constants of the composing components provides a sensitive method to compute the composition of their mixture from its H _w(V) or I _w(V). The method was applied to mixtures of a kind of industrial asphalt and paraffin diluents as an example, and successful results are obtained. __________ Translated from Acta Polymerica Sinica, 2007, 8: 689–692 [译自:高分子学报]