Homogenization by diffusion

The problem of removal of microsegregation by solid-state diffusional processes is reviewed. For most cases of practical interest, volume diffusion coefficients as measured in laboratory couples determine homogenization rates. If the initial distribution of solute is sufficiently regular and well-characterized, the decay of microsegregation can be predicted with good precision. Often, however, order-of-magnitude estimates are all that is required, and these may be made from less complete information. The interactions of diffusing solutes with crystalline defects and with other solutes, are of practical as well as academic interest: in particular, multi-component interactions can significantly influence the course of homogenization. This paper is based on an invited talk presented at a symposium on Homogenization of Alloys, sponsored by the IMD Heat Treatment Committee, and held on May 11, 1970, at the spring meeting of The Metallurgical Society of AIME, in Las Vegas, Nev.     

Effects of herbs on hydrolytic and oxidative degradation of olive oil in canned tomatoes

The effects of adding mixtures of herbs such as garlic, laurel, and marjoram on selected chemical indices of olive oil from canned dried tomatoes were studied for various storage periods of up to 1 yr. Conventional analytical indices measured included acidity, PV, and p-anisidine value. Flavored samples showed kinetic constant values that were significantly (P=0.001) higher than unflavored ones, whereas oligopolymer and oxidized TG and DG contents were similar to or slightly higher than in the unflavored samples compared with those with herbs. The addition of the mixture of herbs slowed polymerization reactions but did not inhibit TG oxidation. Discrepancies between the results obtained by conventional analyses and high-performance size-exclusion chromatography indicated that the former approaches were insufficient to determine oxidative degradation of oil as a result of interferences from compounds in the food matrix.     

Are Chemical Compounds Important for Soybean Resistance to <Emphasis Type="Italic">Anticarsia gemmatalis</Emphasis>?

The identification and quantification of flavonoids (rutin and genistin) present in extracts of soybean genotypes, and their effects on the biology and physiology of Anticarsia gemmatalis Hübner (Lep.: Noctuidae) were studied. Analysis of covariance and bicoordinate utilization plots were used to remove the effect of feeding time from pupal weight and consumption as well as to separate pre- and postingestive effects of treatment on A. gemmatalis growth. Genotypes PI 274454, PI 227687, and “IAC-100” extracts in general, caused higher mortality, negatively influenced initial larval and pupal weight, and elongated larval cycle. Larvae fed on the “IAC-100” extract diet ingested larger amounts of food per unit of time, but were less efficient in its conversion to biomass. Leaf extracts of PI 227687 had the largest concentration of rutin (quercitin 3-O-rhamnosylglucoside), followed by PI 274454, and “IAC-100”; PI 74454 also had the highest genistin (genistein 7-O-glucoside) content. The susceptible cultivar “BR-16” showed only a kaempferol-based flavonoid in its chemical profile, indicating that after successive crosses, secondary compounds responsible for plant defenses were eliminated. Genotypes PI 274454, PI 227687, and “IAC-100” showed accentuated resistance characteristics and were considered inadequate sources for the development of A. gemmatalis. Considering rutin and genistin concentration in these genotypes, it is suggested that flavonoids are important factors conferring resistance to A. gemmatalis.     

Distribution of NGF and NT-3-like protein immunoreactivity in the teleost kidney

By means of immunochemistry and immunohistochemistry, we investigated in the kidney of freshwater and marine teleostean species for the presence and localization of three neurotrophins: nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin (NT)-3. In both species studied, NGF-like and NT-3-like immunoreactivity were present in the kidney with different distribution patterns, while BDNF-like immunoreactivity was never detected. In goldfish, NGF-like and NT-3-like immunoreactivity were identified extensively in cells along part of the arterial branches adjacent to the afferent arterioles. In scorpion fish, NGF-like and NT-3-like immunoreactive cells were observed both on afferent arterioles and on adjacent secondary branches derived from renal arteries. No immunoreactivity was detected in other renal structures. A staining pattern of immunoreactivity similar to that obtained for NGF and NT-3 was detected utilizing S100 antibody as a juxtaglomerular (JG) cell marker. Double immunolabellings NGF/S100 and NT-3/S100 evidenced the coexistence of neurotrophin-like proteins and S100-like protein in the same immunoreactive cells, thus identifying them as juxtaglomerular cells. Western blot analysis revealed the presence of molecules immunoreactive to NGF and NT-3, whose molecular weights were very similar to those of the corresponding mammalian neurotrophins. These findings extend the presence and distribution of NGF-like and NT-3-like IR in the kidney to teleost species, suggesting a probable participation of these proteins in the renal functions of freshwater and marine teleosts.     

Kinetics of the pearlite reaction in Fe−C−Cr

Velocity and spacing measurements on the pearlite reaction in three eutectoid alloys of Cr (0.4, 0.9 and 1.8 wt pct) have been recorded and compared with growth and spacing equations based on a variety of thermodynamic and kinetic models. At high temperatures the reaction is controlled by phase boundary diffusion of Cr while at lower temperatures, a local equilibrium no-partition model with kinetic control by carbon diffusion best represents the data. At intermediate temperatures there is a smooth transition rather than a sharp break betwewn the two regimes. There is a discrepancy between theory and experiment on the slope of the spacingvs inverse under cooling plot which can be removed by assuming that the ferrite-cementite epitaxy improves with the addition of chromium. R. C. SHARMA, formerly with McMaster University     

Psychedelic drug flashbacks: Attentional deficits?

Tested the validity of theories explaining psychedelic flashbacks as manifestations of deficits in attentional processes caused directly or indirectly by a drug. 34 psychedelic drug users experiencing flashbacks were compared with 29 psychedelic drug users not experiencing flashbacks and with 24 non-drug-using controls on a reaction time task with various preparatory intervals. Findings indicate that the flashbackers' attention was comparable to the attention of the nonflashbacking drug users; both drug-using groups did substantially better than the non-drug-using controls. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impact of ultrafiltration and nanofiltration of an industrial fish protein hydrolysate on its bioactive properties

BACKGROUND: Numerous studies have demonstrated that in vitro controlled enzymatic hydrolysis of fish and shellfish proteins leads to bioactive peptides. Ultrafiltration (UF) and/or nanofiltration (NF) can be used to refine hydrolysates and also to fractionate them in order to obtain a peptide population enriched in selected sizes. This study was designed to highlight the impact of controlled UF and NF on the stability of biological activities of an industrial fish protein hydrolysate (FPH) and to understand whether fractionation could improve its content in bioactive peptides. RESULTS: The starting fish protein hydrolysate exhibited a balanced amino acid composition, a reproducible molecular weight (MW) profile, and a low sodium chloride content, allowing the study of its biological activity. Successive fractionation on UF and NF membranes allowed concentration of peptides of selected sizes, without, however, carrying out sharp separations, some MW classes being found in several fractions. Peptides containing Pro, Hyp, Asp and Glu were concentrated in the UF and NF retentates compared to the unfractionated hydrolysate and UF permeate, respectively. Gastrin/cholecystokinin‐like peptides were present in the starting FPH, UF and NF fractions, but fractionation did not increase their concentration. In contrast, quantification of calcitonin gene‐related peptide (CGRP)‐like peptides demonstrated an increase in CGRP‐like activities in the UF permeate, relative to the starting FPH. The starting hydrolysate also showed a potent antioxidant and radical scavenging activity, and a moderate angiotensin‐converting enzyme (ACE)‐1 inhibitory activity, which were not increased by UF and NF fractionation. CONCLUSION: Fractionation of an FPH using membrane separation, with a molecular weight cut‐off adapted to the peptide composition, may provide an effective means to concentrate CGRP‐like peptides and peptides enriched in selected amino acids. The peptide size distribution observed after UF and NF fractionation demonstrates that it is misleading to characterize the fractions obtained by membrane filtration according to the MW cut‐off of the membrane only, as is currently done in the literature. Copyright © 2010 Society of Chemical Industry     

Synergistic effect and quantification of 5'-ribonucleotides in a chicken soup

The international and national regulation permits the addition of flavour enhancers such as monosodium glutamate (MSG) and inosinic and guanilic acids and their fosfated salts (IMP or GMP, respectively) alone or combined to dehydrated mixtures of broths and soups in order to obtain a synergistic. The objectives of this study were: (1) to determine, through a sensorial panel, the synergistic effect on the flavour of a dehydrated chicken soup to which flavour enhancers were added and (2) quantify the 5'-ribonucleotides in such matrix. The intensity of the chicken flavour was determined using a previously trained 6-member panel. The 5'-ribonucleotidos were determined using the HPLC technique. The results using the panel demonstrated that the combination of GMS, IMF and GMF used potentiates significantly (p < 0.05) the flavour of the dehydrated chicken soup, which allows the use of less quantity of them to obtain the same effect on the flavour. The chemical analysis of the 5'-ribonucleotidos in the dehydrated chicken soup reflected a percentage of recovery of 93.6% for MSG and 90.5% for IMF.     

Determination of water quality variables, endotoxin concentration, and Enterobacteriaceae concentration and identification in southern High Plains dairy lagoons

The objectives of this study were to determine the concentration of endotoxin, determine 20 water quality variables, and identify and enumerate fungal and bacterial pathogens from United States southern High Plains dairy lagoons and control lakes during summer and winter. Water samples were collected in triplicate from the north, south, east, and west quadrants of each body of water. The mean (± SEM) winter dairy lagoon endotoxin concentration was significantly higher (9,678 ± 1,834 ng/mL) than the summer concentration (3,220 ± 810 ng/mL). The mean endotoxin concentration of the 2 control lakes (summer: 58.1 ± 8.8 ng/mL; winter: 38.6 ± 4.2 ng/mL) was significantly less than that of the dairy lagoons. Two hundred-one Salmonella enterica spp. isolates were identified, 7 serovars were recovered from the dairy lagoons, and 259 Salmonella ssp. were identified from 5 other dairy locations (milk barn, ditch effluent, settling basin, feed alley pad flush, and center pivots). Twenty-eight Salmonella spp. were identified from center pivot water. Escherichia coli O157:H7 pathogens were isolated from other dairy locations but not from lagoons. Neither Salmonella spp. nor E. coli O157:H7 were identified from control lakes. Enterobacteriaceae opportunistic pathogens were isolated from both dairies and control lakes. Important mesophilic and thermophilic catabolic (to manure biosolids) fungal isolates were identified from dairy effluent locations, but no thermophilic fungal isolates were cultured from the control lakes. Adequate curing of green forage following center pivot irrigation is important to kill lagoon water enteric pathogens, even though the lagoon water is mixed with fresh water. Recirculating lagoon water to flush the feed alley pad, where cows stand while eating, to remove manure and using lagoon water to abate dairy dust in loafing pens and unimproved dairy roads is inconsistent with good environmental practice management.