Phenoxycycloalkylimine Ligated Zirconium Complexes for Ethylene Polymerization:  Formation of Vinyl-Terminated Low Molecular Weight Polyethylenes with High Efficiency

2006 ◽  
Vol 39 (25) ◽  
pp. 8584-8593 ◽  
Author(s):  
Hiroshi Terao ◽  
Sei-ichi Ishii ◽  
Junji Saito ◽  
Sadahiko Matsuura ◽  
Makoto Mitani ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ethylene Polymerization ◽  
High Efficiency ◽  
Low Molecular Weight ◽  
Zirconium Complexes

Systematic studies on dibenzhydryl and pentiptycenyl substituted pyridine-imine nickel(ii) mediated ethylene polymerization

2020 ◽  
Vol 49 (15) ◽  
pp. 4824-4833 ◽  
Author(s):  
Chaoqun Wang ◽  
Yuxing Zhang ◽  
Hongliang Mu ◽  
Zhongbao Jian
Keyword(s):  
Molecular Weight ◽  
Ethylene Polymerization ◽  
Nickel Catalysts ◽  
Low Molecular Weight

Pyridine-imine nickel catalysts bearing different N-aryl/imine substituents were systematically studied for ethylene polymerization to produce low-molecular-weight and branched polyethylenes.

Effect of Molecular Weight of Polycarboxylate-type Superplasticizer on the Rheological Properties of Cement Pastes

2012 ◽  
Vol 20 (8) ◽  
pp. 725-736 ◽  
Author(s):  
Xiongyi Peng ◽  
Conghua Yi ◽  
Xueqing Qiu ◽  
Yonghong Deng
Keyword(s):  
Molecular Weight ◽  
Rheological Properties ◽  
High Molecular Weight ◽  
High Efficiency ◽  
Rheological Behaviour ◽  
Low Molecular Weight ◽  
Cement Pastes ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Dispersing Ability

In order to study the effect of molecular weight of polycarboxylate-type superplasticizer (PC) on the rheological properties of cement pastes, PCs with different molecular weights (low, medium, high) were synthesized, and used as superplasticizers for cement suspensions. The effect of molecular weight of PC on the zeta potential, adsorption, and rheological behaviour of the corresponding cement suspensions were investigated systematically. Among the PCs, PC with a medium molecular weight always produced the lowest apparent viscosity for cement pastes at the same shear rate. Compared to PC with a low molecular weight, PC with a high molecular weight presented a stronger initial dispersing ability and a weaker dispersing stabilizing ability for cement pastes. In addition, PC with a low molecular weight had an advantage over PC with a high molecular weight for reducing the viscosity of paste in the low added dosage or low water/cement ratio, but the latter had the advantage of reducing the viscosity of the paste when the added dosage or water/cement ratio was high. This understanding of the rheological properties of cement pastes incorporating PC will provide an important reference for the application and synthesis of PC with high efficiency.

P1100IMPACT OF THE RELATIONSHIP BETWEEN LOW MOLECULAR WEIGHT PROTEINS REMOVAL EFFICIENCIES AND THE VOLUME OF ALBUMIN LEAKAGE IN HEMODIAFILTRATION THERAPY

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Kenji Sakurai ◽  
Takeshi Saito ◽  
Hiromi Hosoya ◽  
Yoshitaka Kurihara ◽  
Kaori Kurosawa ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Removal Efficiency ◽  
High Efficiency ◽  
Low Molecular Weight ◽  
Efficient Removal ◽  
On Line ◽  
Stokes Radius ◽  
Removal Efficiencies ◽  
The Relationship ◽  
Low Molecular Weight Proteins

Abstract Background and Aims The purpose of hemodiafiltration (HDF) is to remove small- to large molecular weight solutes in order to prevent and treat complications and to improve the prognosis of dialysis patients. Especially, larger low molecular weight proteins (LMWPs) must be removed efficiently. β2-microglobulin (MG) (molecular weight [MW], 11.8 kDa: Stokes radius, 15.6A), is considered as an important marker of dialysis efficiency. However, MW of β2-MG is too small as a marker in HDF. Conversely, α1-MG (MW, 33 kDa: Stokes radius, 28.4A) is the most appropriate marker for evaluation of solute removal efficiency of HDF because of the following reasons: (1) optical molecular size; (2) not very low physiological blood concentration; (3) stable production rate; (4) removal by convection; and (5) accumulation in ESRD. Efficient removal of α1-MG without losing albumin (Alb) (MW,66 kDa: Stokes radius, 35.5A) is impossible even by HDF. In this study, we investigated the relationship between LMWP removal efficiencies and the volume of Alb leakage by analyzing the results of patients undergoing HDF. And we also evaluated the trend of the serum levels of patients who had received high-efficiency HDF for more than three years Method Eighty-seven patients who had received HDF in 2018–2019 were included. The results of HDF (a total of 435 sessions) were analyzed (blood flow rate, 261.5±28.5 mL/min; replacement fluid volume, 48.7 L/s pre-dilution on-line HDF and 14.2 L/s post-dilution on-line HDF). The removal efficiencies of β2-MG, prolactin (PRL), and α1-MG, and the volume of Alb leakage were examined. In addition, the relationship between the removal efficiency of each solute and the volume of Alb leakage was investigated. Changes in serum Alb level were analyzed in 13 patients who continued to receive high-efficiency HDF (the removal rate of α1-MG was 30% or more) for more than three years. Results Analysis of the results (mean ± SD) obtained from a total of 435 sessions (87 patients) showed that the removal rates of β2-MG, PRL, and α1-MG were 80.7 ± 4.5%, 75.8±9.4 and 33.8 ± 9.4%, respectively, and the Alb leakage was 3.9 ± 1.8 g/s. The equations of the approximate curve between Alb leakage and β2-MG, PRL, and α1-MG removal rates were expressed as follows: ï½™= 1.4197ln(x) + 78.972 (R2 = 0.0426), y = 9.7185ln(x) + 64.134 (R2 =0.4632), and ï½™™= 11.225ln(x) + 20.282 (R2 = 0.6191), respectively. These results indicate that the dynamics between Alb leakage and α1-MG removal are very similar. That is, although the molecular weight of Alb is twice as that of α1-MG, the difference in their Stokes radius is 20%; therefore, separate removal of Alb and α1-MG is impossible. The mean serum Alb level in 13 patients who received high-efficiency HDF for 3 years or longer was 3.59 ± 0.23 g/dL in January 2017 and 3.69 ± 0.28 g/dL in December 2019, revealing no changes. Conclusion The efficient removal of larger LMWPs leads to the leakage of Alb. However, an Alb leakage of 3 to 6 g/s has little influence on the serum Alb level of patients. Thus, α1-MG is the most appropriate marker of the solute removal efficiency of HDF.

Bis-cycloheptyl-fused bis(imino)pyridine-cobalt catalysts for PE wax formation: positive effects of fluoride substitution on catalytic performance and thermal stability

2020 ◽  
Vol 49 (27) ◽  
pp. 9425-9437 ◽  
Author(s):  
Qiuyue Zhang ◽  
Ningning Wu ◽  
Junfeng Xiang ◽  
Gregory A. Solan ◽  
Hongyi Suo ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Molecular Weight ◽  
Ethylene Polymerization ◽  
Catalytic Performance ◽  
Cobalt Catalysts ◽  
Low Molecular Weight ◽  
Polymerization Catalysts ◽  
Positive Effects

The depicted ethylene polymerization catalysts exhibited optimal activities at 60 °C forming low molecular weight PE waxes; ortho-F substitution proved beneficial.

Synthesis of Hydrophobically Associating Polymers and the Application as Oil-Displacing Agent

2020 ◽  
Vol 991 ◽  
pp. 185-190
Author(s):  
Rong Jun Zhang ◽  
Jin Lin Zhao ◽  
Xiao Ke Wang ◽  
Zheng Peng Zhou ◽  
Gang Chen
Keyword(s):  
Molecular Weight ◽  
Water Solubility ◽  
High Efficiency ◽  
Low Molecular Weight ◽  
Biological Stability ◽  
Molecular Weight Polymer ◽  
Laboratory Examinations ◽  
Relative Molecular Weight ◽  
Hydrophobically Associating ◽  
Associating Polymers

Polymer plays a function in dominating fluidity in poly-surfactant binary flooding. After optimization and screening, the polymer ought to encounter the demands of terrific water solubility, high-pitched relative molecular weight, substantial viscosifying capability, beneficial injection, good salt opposition of solution, nice biological stability, no pollution to reservoir and environment, wide source, easy transportation and low expense. In this paper, a series of laboratory examinations on high-efficiency composite that floods system for Chang 6 reservoir in Ansai oilfield will be implemented , concentrating on improving and dispensing the existent polymer formulation, and building low molecular weight polymer with colloidal morphology, in order to make it suitable for aim constitution.

Zirconium Complexes Having Phenoxy/Cycloalkylimine Chelate Ligands for the Polymerization of Ethylene for Vinyl-Terminated Low Molecular Weight Polyethylenes

2002 ◽  
Vol 31 (7) ◽  
pp. 740-741 ◽  
Author(s):  
Sei-ichi Ishii ◽  
Makoto Mitani ◽  
Junji Saito ◽  
Sadahiko Matsuura ◽  
Shin-ichi Kojoh ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight ◽  
Zirconium Complexes ◽  
Chelate Ligands

Synthesis of hyperbranched low molecular weight polyethylene oils by an iminopyridine nickel(ii) catalyst

2017 ◽  
Vol 8 (41) ◽  
pp. 6443-6454 ◽  
Author(s):  
Ilaria D'Auria ◽  
Stefano Milione ◽  
Tonino Caruso ◽  
Gabriele Balducci ◽  
Claudio Pellecchia
Keyword(s):  
Molecular Weight ◽  
Diffraction Analysis ◽  
Ethylene Polymerization ◽  
Low Molecular Weight ◽  
X Ray Diffraction ◽  
X Ray

A 6-(2,6-dimethylphenyl)-2-(2,6-diisopropylphenyl)iminopyridine dibromo nickel(ii) complex was synthesized, characterized by X-ray diffraction analysis and tested in ethylene polymerization using diethylaluminumchloride as the cocatalyst.

scholarly journals A Low-Molecular-Weight Polyethylenimine/pDNA-VEGF Polyplex System Constructed in a One-Pot Manner for Hindlimb Ischemia Therapy

Pharmaceutics ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 171 ◽  
Author(s):  
Xiaoshuang Guo ◽  
Zihan Yuan ◽  
Yang Xu ◽  
Xiaotian Zhao ◽  
Zhiwei Fang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gene Delivery ◽  
High Efficiency ◽  
Transfection Efficiency ◽  
Low Molecular Weight ◽  
Physical Interaction ◽  
Hindlimb Ischemia ◽  
One Pot

Peripheral arterial disease (PAD) is often characterized by continued reduction in blood flow supply to limbs. Advanced therapeutic strategies like gene therapy could potentially be applied to limb ischemia therapy. However, developing a gene delivery system with low toxicity and high efficiency remains a great challenge. In this study, a one-pot construction was used to integrate vector synthesis and polyplex fabrication simultaneously in a simple and robust manner. We fabricated an interpenetrating gene delivery network through the physical interaction between low-molecular-weight polyethylenimine (PEI 1.8 kDa) and plasmid DNA (pDNA) and the chemical bonding between PEI and glutaraldehyde (GA), which was named the glutaraldehydelinked-branched PEI (GPEI) polyplex. The final GPEI polyplex system was pH-responsive and biodegradable due to the imine linkage and it could successfully deliver desired vascular endothelial growth factor (VEGF) pDNA. Compared with PEI (25 kDa)/pDNA polyplexes, GPEI polyplexes showed lower cytotoxicity and higher transfection efficiency both in vitro and in vivo. In addition, we demonstrated that GPEI polyplexes could efficiently promote the formation of new capillaries in vivo, which may provide a practicable strategy for clinical hindlimb ischemia therapy in the future.

scholarly journals HepParser: An Intelligent Software Program for Deciphering Low-Molecular-Weight Heparin Based on Mass Spectrometry

2021 ◽  
Vol 9 ◽  
Author(s):  
Hui Wang ◽  
Yu Wang ◽  
Meijie Hou ◽  
Chunming Zhang ◽  
Yaojun Wang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Molecular Weight ◽  
High Efficiency ◽  
High Accuracy ◽  
Low Molecular Weight ◽  
Liquid Chromatography Mass Spectrometry ◽  
High Similarity ◽  
Low Molecular Weight Heparins ◽  
Intelligent Software ◽  
Main Components

Low-molecular-weight heparins (LMWHs) are considered to be the most successful carbohydrate-based drugs because of their wide use as anticoagulants in clinics. The efficacy of anticoagulants made by LMWHs mainly depends on the components and structures of LMWHs. Therefore, deciphering the components and identifying the structures of LMWHs are critical to developing high-efficiency anticoagulants. However, most LMWHs are mixtures of linear polysaccharides which are comprised of several disaccharide repeating units with high similarity, making it extremely challenging to separate and decipher each component in LMWHs. Here, we present a new algorithm named hepParser to decipher the main components of LMWHs automatically and precisely based on the liquid chromatography/mass spectrometry (LC/MS) data. When tested on the general LMWH using hepParser, profiling of the oligosaccharides with different degrees of polymerization (dp’s) was completed with high accuracy within 1 minute. When compared with the results of GlycReSoft on heparan sulfate samples, hepParser achieved more comprehensive and reasonable results automatically.

Sign in / Sign up

Export Citation Format

Share Document