Physiochemical studies

Akerstrom, B. and Bjorck, L., A physiochemical study of protein G, a molecule with unique immunoglobulin G-binding properties, J. Biol. Chem., 261, 10240-10247, 1986. 

According to Herms and Gray 24) studies are needed on the chemical and physical properties of mosquito oils and on the basic effects of oils upon the mosquito larva s physiology, as well as physiochemical studies of oil films on water surfaces. 

Since buffers can be utilized to speed up swelling and deswelling processes, they may be useful even in physiochemical studies in which simple electrolytes are the desired medium. Thus, one might consider using a buffer to accelerate the ionization or deionization of the gel. When ionization equilibrium is established, the buffer can then be exchanged out of the gel by the simple electrolyte. This two step process may be much faster than the single step process using the simple salt by itself. 

In THE PAST DECADE, IMPROVEMENTS IN infrared spectroscopic instrumentation have contributed to significant advances in the traditional analytical applications of the technique. Progress in the application of Fourier transform infrared spectroscopy to physiochemical studies of colloidal assemblies and interfaces has been more uneven, however. While much Fourier transform infrared spectroscopic work has been generated about the structure of lipid bilayers and vesicles, considerably less is available on the subjects of micelles, liquid crystals, or other structures adopted by synthetic surfactants in water. In the area of interfacial chemistry, much of the infrared spectroscopic work, both on the adsorption of polymers or proteins and on the adsorption of surfactants forming so called "self-assembled" mono- and multilayers, has transpired only in the last five years or so. 

In the various sections of this chapter, I will briefly describe the major characteristics of FT-IR, and then relate the importance of these characteristics to physiochemical studies of colloids and interfaces. This book is divided into two major areas studies of "bulk" colloidal aggregates such as micelles, surfactant gels and bilayers and studies of interfacial phenomena such as surfactant and polymer adsorption at the solid-liquid interface. This review will follow the same organization. A separate overview chapter addresses the details of the study of interfaces via the attenuated total reflection (ATR) and grazing angle reflection techniques. 

Hydrogen sulfide, H2S (J]H2S = [H2S] + [HS ] + [S2 ], where [HS ] represents ca. 80% at pH 7.5-7.65 in the Black Sea anoxic interior), is the key chemical compound that defines the direction and origin of many biogeo-chemical cycles in the anoxic zone of the Black Sea. The main goal of this review is to present the contemporary inventory of hydrogen sulfide and sulfur intermediate species, the results of recent physiochemical studies of the bottom convective layer, and to discuss the sulfur isotopic composition of dissolved sulfide and sulfate. This review concludes by presenting the sulfur budget of the Black Sea. 

Until the determination of the NMR structure of mPrP(121-231) in 1996 (Riek et al., 1996), knowledge of the three-dimensional structure of prpc 5 based on optical spectroscopy data (Pan et al., 1993 Safar et al, 1993), a wealth of biochemical observations, and physiochemical studies with synthetic polypeptide fragments of PrP that also included NMR investigations e.g., Zhang et al, 1995 see also Tagliavini et al, 2001). Given the scarcity of experimental data, for PrP as well as for PrP , much effort was devoted to three-dimensional molecular model-... 

Physiochemical studies on poly(phosphazenes)are also an area of active investigation. Certain of these have been mentioned above. MNDO modeling for [NP(OPh>2]n has been carried out by... 

Pollero RJ, Huca G, Brenner RR (1985) Role of hemocytes and plasma on lipid transport in the freshwater mollusc Diplodon delodontus. Comp Biochem Physiol 82A 339-343 Puppione DL, Jensen DF, O Connor JD (1986) Physiochemical study of rock crab lipoproteins. Biochem Biophys Acta 875 563-568... 

Studies by /ells and his collaborators and by Langridge Indicate that not all of the synthetic DNAs have the same structure. X-ray diffraction has indicated that poly fibrous structures of the Watson Crick type. Poly d(A)-poly d(J) forms a structure different from but closely resembling the Watson Crick structure. However, poly d(G) poly d(C), poly d(A-G)-polyd(C-T), and poly d(I-C) poly d(I-C) appear to be quite unlike the Watson Crick structure. Other physiochemical studies substantiate the X-ray diffraction results. 

Physiochemical studies of the jS-D-xylosidase activity of partially purified... 

Physiochemical studies on microemulsions. 7. Dynamics of percolation and energetics of clustering in water/AOT/isooctane and water/AOT/decane w/o microemulsions in the presence of hydrotopes (sodium salicylate, a-napthol, 3-napthol, resorcinol, catechol, hydroquinone, pyrogallol and urea) and bile salt (sodium cholate). J Phys Chem 105, 7145-7154 (b) Hait, S. K., Sanyal, A., and Moulik, S. P. (2002). Physiochemical studies on microemulsions. 8. The effects of aromatic methoxy hydrotropes on droplet clustering and understanding of dynamics of conductance percolation in water/oU microemulsions. J Phys Chem B 106,12642-12650. 

Jolivet J.P., Gzara M., Mazieres J., Lefebvre J. Physiochemical study of aggregahon in silver colloids. J. CoUoid Interface Sci. 1985 107(2) 429-441... 

Schaffer, F. L., Mattern, C. F. T. Infectivity and physiochemical studies on RNA preparations from highly purified poliomyelitis and coxsackie viruses. Fed. Proc. 

In subsequent studies attempting to find a correlation of physicochemical properties and antimicrobial activity, other parameters have been employed, such as Hammett O values, electronic distribution calculated by molecular orbital methods, spectral characteristics, and hydrophobicity constants. No new insight on the role of physiochemical properties of the sulfonamides has resulted. Acid dissociation appears to play a predominant role, since it affects aqueous solubiUty, partition coefficient and transport across membranes, protein binding, tubular secretion, and reabsorption in the kidneys. An exhaustive discussion of these studies has been provided (10). 

The isoxazolecarboxylic acids are the most intensively investigated of the isoxazole derivatives, and a detailed compilation of their physiochemical properties has been made 62HC(17)l,p. 177). Similar studies have also been carried out with the 5-isoxazolones (62HC(17)l,p. 124), and pK values of 1,2-benzisoxazole derivatives are listed in Table 4. 

At the other end of the continuum there exist drugs that act by some as yet undefined general mechanisms. Much work is currently devoted to study of the fine physiochemical structure of medicinal agents in this class. Considerable progress has... 

Barron, E.S.G., Ambrose, J. and Johnson, P. (1955). Studies on the mechanisms of action of ionising radiations XIII. The effect of X-irradiation on some physiochemical properties of proteins. Radiat. Res. 2, 145-152. 

Electrochemical study of biologically active compounds at the O/W interface provides information on physiochemical properties of the compounds at the O/W interface and in the O and W phases or, in short, hydrophobicity or lipophilicity of biologically active compounds, which seems essential to understand their biological effects, including mode of action, structure-activity relationship, delivery, and others. 

Carotenoids are a class of lipophilic compounds with a polyisoprenoid structure. Most carotenoids contain a series of conjugated double bonds, which are sensitive to oxidative modification and cis-trans isomerization. There are six major carotenoids (ji-carotenc, a-carotene, lycopene, P-cryptoxanthin, lutein, and zeaxanthin) that can be routinely found in human plasma and tissues. Among them, p-carotene has been the most extensively studied. More recently, lycopene has attracted considerable attention due to its association with a decreased risk of certain chronic diseases, including cancers. Considerable efforts have been expended in order to identify its biological and physiochemical properties. Relative to P-carotene, lycopene has the same molecular mass and chemical formula, yet lycopene is an open-polyene chain lacking the P-ionone ring structure. While the metabolism of P-carotene has been extensively studied, the metabolism of lycopene remains poorly understood. 

The study of ceramic trade is multidimensional, relating to cultural and physiochemical variables that can only be treated selectively in a progress report. The major lowland Maya site of... 

This article will focus primarily on recent medicinal chemical studies aimed at addressing or studying particular issues which include inherent activity (versus the enzymatic target as well as in whole cells), in vivo efficacy, pharmacokinetics, physiochemical properties and efforts to elucidate salient features... 

It may be useful, however, to consider limited animal studies to examine the pharmacokinetics and duration of action even of a well-known material made by a new route, unless physiochemical analyses show that to be pointless. 

---