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Water Soluble (water + soluble)
Selected Abstractscyclo(, -Asp- ,3 -hVal- ,3 -hLys) , Solid-Phase Synthesis and Solution Structure of a Water Soluble , -Tripeptide.HELVETICA CHIMICA ACTA, Issue 11 2004Preliminary Communication The H2O-soluble cyclic ,3 -tripeptide cyclo(, -Asp- ,3 -hVal- ,3 -hLys) (4) was obtained by on-resin cyclization of the side-chain-anchored , -peptide 3 (Scheme). In aqueous solution, 4 adopts a structure with uniformly oriented amide bonds and all side chains in lateral positions (Fig.,3). [source] Amphiphilic block copolymer micelles for nanoscale drug deliveryDRUG DEVELOPMENT RESEARCH, Issue 1 2006Glen S. Kwon Abstract Amphiphilic block copolymers can assemble into supramolecular core-shell structures, termed ABC micelles, that have proven utility in drug delivery, particularly for drug solubilization. Several examples have entered clinical trials, attesting to the biocompatibility of ABCs and the potential advantages for drug delivery, e.g., low toxicity relative to Cremophor® EL, a surfactant commonly used for drug solubilization. Several examples of ABC micelles demonstrate potential for prolonged circulation in blood. Coupled with novel strategies toward controlled release of drug, nanoscale ABC micelles have tremendous potential for the targeting of antitumor agents, many of which are poorly water soluble and possess dose-limiting toxicity. Drug Dev. Res. 67:15,22, 2006. © 2006 Wiley-Liss, Inc. [source] Synthesis of Functionalized Au Nanoparticles for Protein Detection,ADVANCED MATERIALS, Issue 3 2008R. Jana Aptamer and antibody functionalized Au nanoparticles are synthesized and used for protein detection (see figure). These particles are highly water soluble and as small as 10 nm. However, they are enlarged after a protein binding event to enhance signal sensitivity. A conventional western blot protocol is used to enable detection of the proteins with nanomolar sensitivity, with the naked eye. [source] Simple non-staining method to demonstrate urate crystals in formalin-fixed, paraffin-embedded skin biopsiesJOURNAL OF CUTANEOUS PATHOLOGY, Issue 5 2009Joshua Weaver Background:, Gouty tophi classically occur as nodules over joints and the helix. The ideal fixative for preservation of gout crystals has traditionally been alcohol because the crystals are formalin and water soluble. However, most biopsies are submitted in formalin fixative, which results in dissolution of urate crystals leaving behind a non-specific pale amorphous area. Although complex staining methods to show urate crystals in tissue have been described, the present study elucidates a simple non-staining method utilizing a thick unstained coverslipped microscopy slide that allows detection and confirmation of birefringence of urate crystals in formalin-fixed, paraffin-embedded tissue. Methods:, Twenty-nine cases of cutaneous gouty tophi were evaluated using a hematoxylin-eosin (H&E)-stained section, a 10-,m unstained coverslipped section and a 4-,m unstained coverslipped section. In all cases, the specimen was received and submitted in formalin. Results:, Polarizable crystals were not identified in any of the H&E sections. The use of the thicker unstained coverslipped section was more sensitive than the standard 4 ,m section by recognizing the characteristic urate crystals in 48% and 38% of the cases, respectively. Conclusions:, This inexpensive adjunctive tool can be used to document gout crystals in almost half of skin biopsies. [source] Inactivation of Escherichia coli K-12 in Apple Juice Using Combination of High-Pressure Homogenization and ChitosanJOURNAL OF FOOD SCIENCE, Issue 1 2009S. Kumar ABSTRACT:, Apple juice and apple cider were inoculated with Escherichia coli K-12 and processed using a high-pressure homogenizer to study bacterial inactivation. Seven levels of pressure ranging from 50 to 350 MPa were used in the high-pressure homogenizer. Two types of chitosan (regular and water soluble) with 2 levels of concentration 0.01% and 0.1% were investigated for synergistic effect with high-pressure homogenization for the bacterial inactivation. E. coli K-12 inactivation was evaluated as a function of homogenizing pressure at different concentration of 2 types of chitosan in apple juice and cider. High-pressure homogenization (HPH) induced significant inactivation in the range of 100 to 200 MPa, while thermal inactivation was the primary factor for the bacterial inactivation above 250 MPa. Significant (P < 0.05) 2-way interactions involving pressure and type of substrate or pressure and chitosan concentration were observed during the study. The homogenization pressure and the incremental quantity of chitosan (both types) acted synergistically with the pressure to give higher inactivation. Significantly (P < 0.05) higher inactivation was observed in apple juice than apple cider at same homogenizing pressure. No effect of type of chitosan was observed on the bacterial inactivation. [source] EXTRACELLULAR MATRIX ASSEMBLY IN DIATOMS (BACILLARIOPHYCEAE).JOURNAL OF PHYCOLOGY, Issue 2 2006The effects of phosphate (P) limitation, varying salinity (5,65 psu), and solid media growth conditions on the polysaccharides produced by the model diatom, Phaeodactylum tricornutum Bohlin were determined. Sequential extraction was used to separate polymers into colloidal (CL), colloidal extracellular polymeric substances (cEPS), hot water soluble (HW), hot bicarbonate soluble (HB), and hot alkali (HA) soluble fractions. Media-soluble polymers (CL and cEPS) were enriched in 4-linked mannosyl, glucosyl, and galactosyl residues as well as terminal and 3-linked xylosyl residues, whereas HW polymers consisted mainly of 3-linked glucosyl as well as terminal and 2,4-linked glucuronosyl residues. The HB fraction was enriched in terminal and 2-linked rhamnosyl residues derived from the mucilage coating solubilized by this treatment. Hot alkali treatment resulted in the complete dissolution of the frustule releasing 2,3- and 3-linked mannosyl residues. The fusiform morphotype predominated in standard and P-limited cultures and cultures subjected to salinity variations, but growth on solid media resulted in an enrichment of the oval morphotype. The proportion and linkages of 15 residues, including neutral, uronic acid, and O -methylated sugars, varied with environmental conditions. P limitation and salinity changes resulted in 1.5- to 2.5,fold increase in carbohydrate production, with enrichment of highly branched/substituted and terminal rhamnose, xylose, and fucose as well as O -methylated sugars, uronic acids, and sulfate. The increased deoxy- and O -methylated sugar content under unfavorable environments enhances the hydrophobicity of the polymers, whereas the anionic components may play important roles in ionic cross-linking, suggesting that these changes could ameliorate the effects of salinity or P-stress and that these altered polysaccharide characteristics may be useful as bioindicators for environmental stress. [source] 163 Identification of Euglenoids That Produce Ichthyotoxin(S) (Euglenophyta)JOURNAL OF PHYCOLOGY, Issue 2003R. E. Triemer Diatoms, dinoflagellates, pelagiophytes, prymnesiophytes, and cyanobacteria are the only divisions of microalgae known to produce toxins. We now report toxin production by freshwater members of the genus Euglena. Fish mortalities (sheepshead minnows, catfish, striped bass, and tilapia) have been observed following exposure in the field to Euglena blooms and in the laboratory when exposed to unialgal isolates of two species of Euglena (E. sanguinea Ehrenberg and E. granulata (Klebs) Lemm.). Three toxic fractions have been isolated from unialgal isolates of both species, and include both water soluble and lipophilic compounds having ichthyotoxic activity. The toxins are stable at ,80°C for at least 60 days and are heat stable to 30°C. Erratic swimming behavior of fish suggests a neurological toxin. This is the first report of fish kills by any freshwater algal taxa from both field and laboratory studies. [source] Synthesis and characterization of synthetic polymer colloids colloidally stabilized by cationized starch oligomersJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 7 2009Marianne Gaborieau Abstract A method is developed for anchoring enzymatically degraded cationized starch as electrosteric stabilizers onto synthetic latices, using cerium(IV) to create free-radical grafting sites on the starch. Direct anchoring of debranched starch onto a poly(methyl methacrylate) seed latex yields a latex stabilized by well-defined oligosaccharides. Using ,-amylase to randomly cleave starch to form (1,4)-,-glucans, and a comonomer, N -isopropyl acrylamide (NIPAM), whose corresponding polymer exhibits a lower critical solution temperature (LCST), creates a means to synthesize block (or graft) oligomers of oligosaccharide and synthetic polymer, which are water soluble at room temperature. Above 30 °C, they become amphiphilic and form self-emulsifying nanoparticles (sometimes termed "frozen micelles") from which a synthetic latex is grown after addition of methyl methacrylate, the collapsed NIPAM-containing entities functioning as a type of in situ seed. This synthesis of stable synthetic latex particles is shown to have a high grafting efficiency. The starch fragments were characterized by 1H solution-state NMR before grafting, and 13C solid-state cross-polarization magic-angle spinning (CP-MAS) NMR was used to characterize the starch oligomers actually grafted on the final latex. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1836,1852, 2009 [source] New Biodegradable Amphiphilic Block Copolymers of , -Caprolactone and , -Valerolactone Catalyzed by Novel Aluminum Metal ComplexesMACROMOLECULAR BIOSCIENCE, Issue 9 2005Jing Yang Abstract Summary: In our previous study [J. Yang, L. Jia, L. Yin, J. Yu, Z. Shi, Q. Fang, A. Cao, Macromol. Biosci.2004, 4, 1092.], new biodegradable copolymers of diblock methoxy poly(ethylene glycol)- block -poly(, -caprolactone) and methoxy poly(ethylene glycol)- block -poly(, -valerolactone), and triblock poly(, -caprolactone)- block -poly(ethylene glycol)- block -poly(, -caprolactone) and poly(, -valerolactone)- block -poly(ethylene glycol)- block -poly(, -valero-lactone) bearing narrow molecular weight distributions and well-defined block architectures were reported to be prepared with our original aluminum metal complex templates. This work will continue to report new investigations on their water solubility, and reversible thermal responsive micellization and solution to gel transition in distilled water. Among the new synthesized copolymers (P1,P23), seven diblock or triblock samples (P3, P6, P7, P11, P12, P19, and P21) with higher hydrophilic building block populations were revealed to be water soluble under ambient temperature. By means of UV spectrophotometer attached with a thermostat, important parameters as critical micellization mass concentrations (CMCs) and critical micellization temperatures (CMTs) were characterized for these new amphiphile dilute aqueous solution with the aid of an lipophilic organic dye probe of 1,6-diphenyl-1,3,5-hexatriene (DPH). Furthermore, the critical gelation temperatures (CGTs) were simultaneously investigated for these water-soluble block copolymers via a tube tilting method. It was found that the CMC, CMT, and CGT were strongly affected by the population and nature of the hydrophobic building blocks, and a higher hydrophobicity of the new amphiphilic block copolymer finally led to lower CMC and CMT, and higher CGT. In addition, the salts of KBr and NaCl were found to play as a salt-out effect on the solution to gel transition for the diblock P6 and triblock P11, exhibiting an interesting tunable gelation temperature close to 35,42,°C. These results will pave new possibility for the synthesized block structural amphiphiles as potential biomaterials to be applied in vivo. Thermal responsive micellization and gelation of diblock MPEG- b -PCL/PVL and triblock PVL/PCL- b -PEG- b -PCL/PVL. [source] 1H- and 31P-MR spectroscopy of primary and recurrent human brain tumors in vitro: malignancy-characteristic profiles of water soluble and lipophilic spectral componentsNMR IN BIOMEDICINE, Issue 5 2001Fritz-Georg Lehnhardt Abstract In vitro NMR spectrocopy was performed on specimen of human brain tumors. From all patients, tissue samples of primary tumors and their first recurrences were examined. 31P- and 1H-spectra were recorded from samples of meningioma, astrocytoma and glioblastoma. A double extraction procedure of the tissue samples permitted acquisition of information from the membrane fraction and from the cytosolic fraction. 31P-spectra were used to analyze the lipophilic fraction (phospholipids of the membrane) of the tissue extracts, while the 1H-spectra reflected information on the metabolic alterations of the hydrophilic, cytosolic fraction of the tissue. The tumor types showed distinctive spectral patterns in both the 31P- and the 1H-spectra. Based on the total detectable 31P signal, the level of phosphatidylcholine was about 34% lower in primary astrocytomas than in primary glioblastomas (p,=,0.0003), whereas the level of sphingomyelin was about 45% lower in primary gioblastomas than in primary astrocytomas (p,=,0.0061). A similar tendency of these phospholipids was observed when comparing primary and recurrent astrocytoma samples from the same individuals [+15% (p,=,0.0103) and ,23% (p,=,0.0314) change, respectively]. 1H-spectra of gliomas were characterized by an increase of the ratios of alanine, glycine and choline over creatine as a function of the degree of malignancy. In agreement with findings in the 31P-spectra, the 1H-spectra of recurrent astrocytomas showed metabolic profiles of increased malignancy in comparison to their primary occurrence. Since gliomas tend to increase in malignancy upon recurrence, this may reflect evolving tumor metabolism. 1H-spectra of meningiomas showed the highest ratio of alanine over creatine accompanied by a near absence of myo-inositol. Phospholipid profiles of meningiomas showed higher fractional contents of phosphatidylcholine along with lower phosphatidylserine compared to astrocytomas, while higher phosphatidylethanolamine and sphingomyelin fractional contents distinguished meningiomas from glioblastomas. The extraction method being used in this study combined with high-resolution 1H- and 31P-MRS provides a wide range of biochemical information, which enables differentiation not only between tumor types but also between primary and recurrent gliomas, reflecting an evolving tumor metabolism. Copyright © 2001 John Wiley & Sons, Ltd. [source] Stimuli-responsive water soluble and amphiphilic polymers,ACS Symposium Series 780 Edited by C,L McCormick American Chemical Society (distributed by Oxford University Press), Washington, 2001 pp xii,+,352, Price $125.00 ISBN 08412 37255POLYMER INTERNATIONAL, Issue 8 2002A Finch No abstract is available for this article. [source] Protein adsorption and platelet adhesion of polysulfone membrane immobilized with chitosan and heparin conjugatePOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 2 2003M.-C. Yang Abstract Polysulfone (PSF) membranes were treated with ozone to introduce peroxides, and then grafted with either acrylic acid or chitosan, followed by the immobilization of heparin. The effect of spacer arm on blood compatibility was investigated using three chitosans of different molecular weight [1170 (water soluble), 160,000, and 400,000] and similar degrees of deacetylation (75%). The hydrophilicity was evaluated by measuring the contact angle of water. Blood compatibility was evaluated using the activated partial thromboplastin time (APTT) as well as the adhesion of platelets. The protein affinity was determined by the absorption of human serum albumin (HSA) and human plasma fibrinogen (HPF). The results show that by the coupling of chitosan, the amount of heparin immobilized can be increased by four times. Water contact angle (from 78,° to 41,°) decreased with the increase of the amount of heparin immobilized, showing increased wettability. The heparinized PSF membrane showed longer APTT and decreasing platelet adhesion, compared to that of unmodified PSF membrane. The adsorption of HSA and HPF were reduced to 17 and 6%, respectively. This suggests that longer spacer binding to heparin can increase the opportunity of anti-coagulation on contacting blood. These results demonstrated that the hydrophilicity and blood compatibility of PSF membrane could be improved by chitosan and heparin conjugate. Copyright © 2003 John Wiley & Sons, Ltd. [source] Methylene as a possible universal footprinting reagent that will include hydrophobic surface areas: Overview and feasibility: Properties of diazirine as a precursorPROTEIN SCIENCE, Issue 12 2000Frederic M. Richards Abstract Methylene is one of, if not the, most reactive organic chemical known. It has a very low specificity, which makes it essentially useless for synthesis, but suggests a possible role in protein footprinting with special importance in labeling solvent accessible nonpolar areas, identifying ligand binding sites, and outlining interaction areas on protomers that form homo or hetero oligomers in cellular assemblies. The singlet species is easily and conveniently formed by photolysis of diazirine. The reactions of interest are insertion into C-H bonds and addition to multiple bonds, both forming strong covalent bonds and stable compounds. Reaction with proteins and peptides is reported even in aqueous solutions where the vast majority of the reagent is used up in forming methanol. Species containing up to 5 to 10 extra : CH2 groups are easily detected by electrospray mass spectroscopy. In a mixture of a 14 Kd protein and a noninteracting 1.7 Kd peptide, the distribution of mass peaks in the electrospray spectra was close to that expected from random modification of the estimated solvent accessible area for the two molecules. For analysis at the single residue level, quantitation at labeling levels of one 13CH2 group per 10 to 20 kDa of protein appears to be possible with isotope ratio mass spectroscopy. In the absence of reactive solvents, photolysis of diazirine produces oily polymeric species that contain one or two nitrogen atoms, but not more, and are water soluble. [source] Effects of steroid hormones on five functional parameters of Tetrahymena: evolutionary conclusionsCELL BIOCHEMISTRY AND FUNCTION, Issue 1 2003László K, hidai Abstract The unicellular Tetrahymena pyriformis was studied for chemotaxis, chemotactic selection, phagocytosis, growth and body shape changes in the presence of water soluble (,-cyclodextrin-coupled) steroid hormones (testosterone, estradiol, progesterone, hydrocortisone and dexamethasone). Testosterone was chemoattractant over a wide range of concentrations, while progesterone and dexamethasone were active only at one concentration (10,5 and 10,6,mg,ml,1 respectively) and were either neutral or repellent at other concentrations. Hydrocortisone and estradiol were unambiguously chemorepellent. Chemotactic selection enhanced the effect of testosterone and estradiol, while in the case of hydrocortisone the action was reversed. The other parameters were mildly influenced by the steroid hormones. The results call attention to the fine molecular recognition capacity of Tetrahymena and to the possible rapid effects of steroid hormones at membrane receptors at a very low evolutionary eukaryotic level. Copyright © 2002 John Wiley & Sons, Ltd. [source] A Lanthanide-Complex-Based Ratiometric Luminescent Probe Specific for PeroxynitriteCHEMISTRY - A EUROPEAN JOURNAL, Issue 22 2010Cuihong Song Abstract A lanthanide-complex-based ratiometric luminescence probe specific for peroxynitrite (ONOO,), 4,-(2,4-dimethoxyphenyl)-2,2,:6,,2,,-terpyridine-6,6,,-diyl]bis(methylenenitrilo)tetrakis(acetate)-Eu3+/Tb3+ ([Eu3+/Tb3+(DTTA)]), has been designed and synthesized. Both [Eu3+(DTTA)] and [Tb3+(DTTA)] are highly water soluble with large stability constants at ,1020, and strongly luminescent with luminescence quantum yields of 10.0 and 9.9,%, respectively, and long luminescence lifetimes of 1.38 and 0.26,ms, respectively. It was found that the luminescence of [Tb3+(DTTA)] could be quenched by ONOO, rapidly and specifically in aqueous buffers, while that of [Eu3+(DTTA)] did not respond to the addition of ONOO,. Thus, by simply mixing [Eu3+(DTTA)] and [Tb3+(DTTA)] in an aqueous buffer, a ratiometric luminescence probe specific for time-gated luminescence detection of ONOO, was obtained. The performance of [Tb3+(DTTA)] and [Eu3+/Tb3+(DTTA)] as the probes for luminescence imaging detection of ONOO, in living cells was investigated. The results demonstrated the efficacy and advantages of the new ratiometric luminescence probe for highly sensitive luminescence bioimaging application. [source] Quaternary reactive dyes containing a thioether-ethylsulphone group.COLORATION TECHNOLOGY, Issue 6 2003Part 2; Application methods for the dyeing of nylon A member of the new series of cationic reactive dyes containing a thioether-ethylsulphone grouping referred to in Part 1 of this series has been applied to nylon at pH 3,10. The dye is water soluble and shows excellent substantivity for nylon 6.6 when dyed at the boil at pH 8,10. Under alkaline conditions, gradual ,-elimination back to the vinylsulphone dye occurs and covalent bond formation quickly takes place with the fibre; the higher the pH the more rapidly this occurs. Dyeings carried out at pH 10 showed very good brightness and levelling, together with good wash fastness. The light fastness of dyeings at moderate depth was 4,5 on the Blue Wool scale. [source] | |||||||||||||||||||