It is an object of the present invention to provide a thickener capable of exhibiting excellent light resistance. The present invention relates to a thickener comprising cellulose fibers having a fiber width of 8 nm or less and water, wherein the thickener is a slurry or a gel, and when the thickener is filled in a colorless and transparent glass cell having an inside dimension of 1 cm in depth×4 cm in width×4.5 cm in height and the thickener is then irradiated with ultraviolet rays with a wavelength of 300 nm or more and 400 nm or less, using a xenon lamp, from the side of the maximum area surface of the glass cell, so as to be an irradiance of 180 W/m.sup.2 and an integrated light amount of 500 mJ/m.sup.2, the amount of a change in the yellowness before and after ultraviolet irradiation measured in accordance with JIS K 7373 is 10 or less.

Dry solids of anionically modified cellulose nanofibers with good redispersion are provided by incorporating 5 to 300% by mass of a water-soluble polymer relative to the anionically modified cellulose nanofibers during the preparation of the dry solids of anionically modified cellulose nanofibers.

Dry solids of anionically modified cellulose nanofibers with good redispersion are provided by incorporating 5 to 300% by mass of a water-soluble polymer relative to the anionically modified cellulose nanofibers during the preparation of the dry solids of anionically modified cellulose nanofibers.

A method for controlling the catalytic oxidation of cellulose includes using a heterocyclic nitroxyl compound as catalyst oxidizing cellulose in a reaction mixture comprising liquid medium, the catalyst and hypochlorite as main oxidant analyzing one or more oxidative chlorine species dependent on the hypochlorite concentration of the reaction mixture on line in the reaction mixture or in a gas composition which is in contact with the reaction mixture; and controlling supply of hypochlorite to the reaction mixture on the basis of the analysis.

A method for controlling the catalytic oxidation of cellulose includes using a heterocyclic nitroxyl compound as catalyst oxidizing cellulose in a reaction mixture comprising liquid medium, the catalyst and hypochlorite as main oxidant analyzing one or more oxidative chlorine species dependent on the hypochlorite concentration of the reaction mixture on line in the reaction mixture or in a gas composition which is in contact with the reaction mixture; and controlling supply of hypochlorite to the reaction mixture on the basis of the analysis.

A process for producing an oxidized nanofibrillar cellulose hydrogel is disclosed, wherein the process comprises oxidizing cellulose pulp fibers in the presence of hypochlorite as an oxidant and a heterocyclic nitroxyl radical as a catalyst; and disintegrating the oxidized cellulose pulp fibers to obtain a nanofibrillar cellulose hydrogel; wherein all steps of the process after oxidizing are performed under aseptic conditions. An oxidized nanofibrillar cellulose hydrogel and a system for producing the same are also disclosed.

A process for producing an oxidized nanofibrillar cellulose hydrogel is disclosed, wherein the process comprises oxidizing cellulose pulp fibers in the presence of hypochlorite as an oxidant and a heterocyclic nitroxyl radical as a catalyst; and disintegrating the oxidized cellulose pulp fibers to obtain a nanofibrillar cellulose hydrogel; wherein all steps of the process after oxidizing are performed under aseptic conditions. An oxidized nanofibrillar cellulose hydrogel and a system for producing the same are also disclosed.

Provided is an oxidized microfibrillated cellulose fiber having a Canada standard freeness of not less than 200 mL and an average fiber diameter of not less than 500 nm. Said fiber enhances paper strength when added to a paper.

Several embodiments of NO releasing structures are disclosed. In some embodiments, the structures are covalently modified to store and release nitric oxide. Some embodiments pertain to methods of making and use of these structures. The covalently modified polymer structures may be tailored to release nitric oxide in a controlled manner and are useful for treatment of various medical conditions.

Several embodiments of NO releasing structures are disclosed. In some embodiments, the structures are covalently modified to store and release nitric oxide. Some embodiments pertain to methods of making and use of these structures. The covalently modified polymer structures may be tailored to release nitric oxide in a controlled manner and are useful for treatment of various medical conditions.