Disclosed are methods and systems that include obtaining at least one image of a dendritic structure, analyzing the at least one image to identify one or more features associated with the dendritic structure, and determining a numerical value associated with the dendritic structure based on the one or more features.

A process of forming a bottlebrush polymer includes forming a poly(methylidenelactide) (PML) material from an L-lactide molecule. The process also includes forming a lactide feedstock that includes a blend of a first amount of an L-lactide monomer and a second amount of the PML material. The process further includes polymerizing the lactide feedstock to form a bottlebrush polymer.

A process of forming a bottlebrush polymer includes forming a poly(methylidenelactide) (PML) material from an L-lactide molecule. The process also includes forming a lactide feedstock that includes a blend of a first amount of an L-lactide monomer and a second amount of the PML material. The process further includes polymerizing the lactide feedstock to form a bottlebrush polymer.

Disclosed are an eight-arm polyethylene glycol (PEG) derivative (formula I), production method therefor and modified bio-related substance thereby. Wherein, one tetravalent group U together with four trivalent groups E.sub.c form a highly symmetrical octavalent group CORE.sub.0; L.sub.c connects the octavalent group to eight PEG chains having polydispersity or monodispersity and having n.sub.1 to n.sub.8 as the degree of polymerization thereof; the terminal of one PEG chain is connected to at least one functional group F (k1); said PEG chain and F therebetween can be directly connected (g=0) or be indirectly connected via a linking group L.sub.0 to a terminal end-branching group G (g=1); the latter provides more reactive sites for binding more drug molecules and increases the drug loading. The eight-arm polyethylene glycol derivative has a centrosymmetric or approximately centrosymmetric structure, and leads to more precise control of the molecular weight in large-scale production and much narrower distribution of molecular weight for products. The modified bio-related substance thereby has a more uniform and controllable performance.

##STR00001##

Conjugates of SN-38 that provide optimal drug release rates and minimize the formation of the corresponding glucuronate are described. The conjugates release SN-38 from a polyethylene glycol through a -elimination mechanism.

Methods may include emplacing into a hydrocarbon production stream a composition containing an asphaltene inhibitor, wherein the asphaltene inhibitor includes the formula:

##STR00001##

wherein R1 is an alkyl chain having a carbon number in the range of greater than 40 to 200, R2 is a multiester group, R3 is hydrogen, an ion, or an alkyl chain having a carbon number in the range of 1 to 200, m is an integer selected from 0 to 4, and n is an integer selected from the range of 0 to 4, wherein the sum of m and n is 1 or greater. Methods may also include emplacing in a wellbore a composition containing an asphaltene inhibitor, wherein the asphaltene inhibitor comprises esters of the formula:

##STR00002##

wherein R1 is an alkyl chain having a carbon number in the range of greater than 40 to 200; R2 is a multiester group; is hydrogen, an ion, or an alkyl chain having a carbon number in the range of 1 to 200; m is an integer selected from 0 to 4; and n is an integer selected from the range of 0 to 4, wherein the sum of m and n is 1 or greater.

Disclosed is a pharmaceutical composition for treating hyperuricemia (HUA). The pharmaceutical composition includes a polysaccharide-polyamine copolymer and a pharmaceutically acceptable salt thereof as active ingredients. The polysaccharide-polyamine copolymer is formed by copolymerization of the following two parts: a selectively oxidized polysaccharide with 2,3-dialdehydo, and a polyamine with an amino functional group; the polyamine with an amino functional group and the selectively oxidized polysaccharide with 2,3-dialdehydo can form a net structure by means of covalent crosslinking, resulting in a hydrogel with an amino functional group or a granular polysaccharide-polyamine copolymer, wherein the amino functional group in the hydrogel with an amino functional group or the granular polysaccharide-polyamine copolymer can be protonated so as to form a cationic copolymer of a three-dimensional network structure having a protonated site, and the nitrogen content of the cationic copolymer and the nitrogen content of the polysaccharide-polyamine copolymer are above 12.3 wt %, and both the cationic copolymer and the polysaccharide-polyamine copolymer are water-insoluble.

Covalently cross-linked copolymers are described herein. More specifically, polysaccharide-polyamine copolymeric matrices or structures and cationic copolymeric matrices are described herein. The polysaccharide-polyamine copolymers, when protonated, can form cationic copolymeric matrices having exceptionally high densities of cationic sites. In one form, the covalently cross-linked copolymers provide a three-dimensional structure, especially when hydrated.

Disclosed is a pharmaceutical composition for treating hypercholesterolemia. The pharmaceutical composition includes a polysaccharide-polyamine copolymer and a pharmaceutically acceptable salt thereof as active ingredients. The polysaccharide-polyamine copolymer is formed by copolymerization of the following two parts: a selectively oxidized polysaccharide with 2,3-dialdehyde, and a polyamine with an amino functional group; the polyamine with an amino functional group and the selectively oxidized polysaccharide with 2,3-dialdehyde can form a net structure by means of covalent crosslinking, resulting in a hydrogel with an amino functional group or a granular polysaccharide-polyamine copolymer, wherein the amino functional group in the hydrogel with an amino functional group or the granular polysaccharide-polyamine copolymer can be protonated so as to form a cationic copolymer of a three-dimensional network structure having a protonated site, and the nitrogen content of the cationic copolymer and the nitrogen content of the polysaccharide-polyamine copolymer are above 12.3 wt %, and both the cationic copolymer and the polysaccharide-polyamine copolymer are water-insoluble.

Covalently cross-linked copolymers are described herein. More specifically, polysaccharide-polyamine copolymeric matrices or structures and cationic copolymeric matrices are described herein. The polysaccharide-polyamine copolymers, when protonated, can form cationic copolymeric matrices having exceptionally high densities of cationic sites. In one form, the covalently cross-linked copolymers provide a three-dimensional structure, especially when hydrated.