ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCarbon-13 nuclear magnetic resonance spectrometry with cross polarization and magic-angle spinning for analysis of lodgepole pine woodWaclaw. Kolodziejski, James S. Frye, Gary E. MacielCite this: Anal. Chem. 1982, 54, 8, 1419–1424Publication Date (Print):July 1, 1982Publication History Published online1 May 2002Published inissue 1 July 1982https://pubs.acs.org/doi/10.1021/ac00245a035https://doi.org/10.1021/ac00245a035research-articleACS...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCarbon-13 NMR and order in celluloseGary E. Maciel, Waclaw L. Kolodziejski, Maria S. Bertran, Bruce DaleCite this: Macromolecules 1982, 15, 2, 686–687Publication Date (Print):March 1, 1982Publication History Published online1 May 2002Published inissue 1 March 1982https://pubs.acs.org/doi/10.1021/ma00230a097https://doi.org/10.1021/ma00230a097research-articleACS PublicationsRequest reuse permissionsArticle Views270Altmetric-Citations91LEARN ABOUT...

Structural and spectroscopic properties of hydrogen bonding in solid 5-nitro-N-salicylideneethylamine have been investigated. This is the first example ionic [O-···H−N+] intramolecular a structure Schiff base. Single-crystal X-ray diffraction 13C magic-angle spinning NMR show that title molecule dominated by canonical structures favored through conjugation between nitro group both groups salicylidene fragment. Being involved strong [O-··· H−N+] bonding, forms its crystal lattice means...

Herein, we present a convenient method for quantitative spectrophotometric determination of citrate ions in aqueous solutions the middle-UV range. It involves measuring absorbance citric acid at 209 nm under suppressed dissociation pH < 1.0 presence hydrochloric acid. Validation was performed according to guidelines International Conference on Harmonization. A very good linear dependence concentration (r2 = 0.9999) obtained range 0.5-5.0 mmol/L. This is characterized by excellent precision...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXT27Al and 29Si MAS NMR Study of Zeolite MCM-22Waclaw Kolodziejski, Claudio Zicovich-Wilson, Catalina Corell, Joaquin Perez-Pariente, Avelino CormaCite this: J. Phys. Chem. 1995, 99, 18, 7002–7008Publication Date (Print):May 1, 1995Publication History Published online1 May 2002Published inissue 1 1995https://pubs.acs.org/doi/10.1021/j100018a037https://doi.org/10.1021/j100018a037research-articleACS PublicationsRequest reuse permissionsArticle...

The concentration of structural hydroxyl groups in the apatite mineral enamel, dentin and cementum healthy human teeth was estimated by reference to stoichiometric hydroxyapatite be 73 ± 3, 18 2 1%, respectively.

The pharmacy is one of the most important areas in which macromolecular compounds are applied. They used as pharmacological substances, blood substitutes, various auxiliary materials or excipients well production prodrugs, polymeric drug delivery systems, therapeutic etc. (Table 1 and 2). systems characterized with unique pharmacokinetics, ability to distribute precisely drugs organism efficiency. In this paper natural, modified synthetic polymers examples their applications were described.

Abstract A series of biomedical polyurethane elastomers (PURs) based on poly(ester‐carbonate)s (PECs) and polycarbonates (PCs) were synthesized spectrally characterized fully. PEC or PC diols by the ring‐opening polymerization ε‐caprolactone, trimethylene carbonate, neopentyl carbonate catalyzed lipase from Candida antarctica . PURs prepared free‐metal method 4,4′‐methylenebis(phenyl isocyanate), with 1,4‐butanediol as a chain extender. The physical mechanical properties well hydrolytic...

A series of nanocrystalline calcium hydroxyapatites was prepared by dry milling and characterized using proton 31P MAS NMR, TEM, TGA methods. The samples contained stubby rod-shaped crystals, which length width varied in the 130-30 95-20 nm ranges, respectively. It confirmed that concentration structural hydroxyl groups apatites decreases with decreasing crystal size. In studied apatites, decrease from 86 to ca. 50 % reference stoichiometric apatite. Water found surface hydrated layer c-axis...

Near-infrared spectroscopy (NIR) was used to analyze synthetic hydroxyapatite calcined at various temperatures, carbonated hydroxyapatite, and human hard dental tissues (enamel dentin). The NIR bands of those materials in the combination, first-overtone, second-overtone spectral regions were assigned evaluated for structural characterization. They attributed adsorbed water, hydroxyl (OH) groups surface P–OH groups. features quantitatively discussed view proton solid-state magic-angle...

Abstract Multiple chlorinations and arylations at the tertiary positions of adamantane are promoted by FeCl 3 ‐doped K10 montmorillonite in CCl 4 or aromatic solvents. The process, remarkably easy to implement, can be tailored selective formation monosubstituted 1‐adamantyl derivatives 1,3‐disubstituted adamantanes. process achieves alkylation meta ‐ para ‐positions toluene leading a purely statistical distribution displays no substrate specificity competition experiments between benzene.

Two-, three- and four-arm, star-shaped poly(ε-caprolactone) andpoly(D,L-lactide) homopolymers, copolymers of ε-caprolactone with D,L-lactide weresynthesized via ring-opening polymerization cyclic esters in the presence glycerol,penthaerythritol poly(ethylene glycol) as initiators stannous octoate a catalyst.Thus obtained oligomers were successfully used synthesis novel macromolecularprodrugs norfloxacin. The structures polymers prodrugs elucidated bymeans MALDI-TOF MS, NMR IR studies.

Abstract Kinetics of NMR cross‐polarization (CP) from protons to phosphorus‐31 nuclei was studied in the following samples: mineral whole human bone, apatite prepared natural brushite, synthetic hydroxyapatite (hydrated and calcined), carbonatoapatite type B with 9 wt% CO 3 2− . In order avoid an effect magic angle spinning on CP relaxation, experiments were carried out static samples. Parameters kinetics discussed for trabecular cortical bone tissue adult subjects comparison standards. It...