Mechanical improvement of concrete by irradiated polypropylene fibers

Fiber reinforced concrete (FRC) contains fibers physically mixed with gravel, sand, cement, and water. So far, adequate mechanical performance of FRC has been obtained at high cost and using complex technologies; important here is the geometry and surface characteristics of the polymers. We have modified polymeric‐fiber surfaces by using gamma radiation. Irradiated polypropylene (PP) fibers were submitted to 0, 5, 10, 50, and 100 kGy of gamma irradiation dosages. First, tensile strength of PP fibers was evaluated, and then fibers blended at 0, 1.0, 1.5, and 2.0% in volume with Portland cement, gravel, sand, and water. The highest values of compressive strength were obtained with irradiated‐fibers at 10 kGy and 1.5% in volume of fiber. The result is 101 MPa, as compared to 35 MPa for simple concrete without fibers. POLYM. ENG. SCI., 45:1426–1431, 2005. © 2005 Society of Plastics Engineers     

Compulsory notification of cysticercosis in Ribeir?o Preto-SP, Brazil

Cysticercosis is a severe public health problem in several regions of Asia, Africa and Latin America. Epidemiologic studies based on the frequency of cases observed in specialized neurology, neurosurgery and computed tomography services, at autopsy and in seroepidemiologic studies do not permit the determination of the true prevalence of the disease in the population. The objective of the present study was to investigate the prevalence of cysticercosis by compulsory notification. The coefficient of prevalence was 54 cases/100,000 inhabitants in the municipality of Ribeir?o Preto. The results also indicated that cysticercosis is not under control in our region since 21% of cases presented the active form of the disease. Compulsory notification proved to be a valuable resource for the epidemiologic study of cysticercosis, also permitting the mapping of more affected areas for a better direction of prevention strategies.     

Lipid damage in farmed rainbow trout (Oncorhynchus mykiss) after slaughtering and chilled storage

The flow ice system including ozone (OFI condition) was tested for slaughtering and storage (up to 16 days) of farmed rainbow trout (Oncorhynchus mykiss). Lipid damage analyses were carried out and compared to sensory acceptance and instrumental colour changes. Comparison to individuals processed with the flow ice system in the absence of ozone (FI condition) was undertaken. Rainbow trout slaughtered and chilled under FI and OFI conditions showed a low lipid damage development, according to lipid oxidation and hydrolysis events and lipid composition (polyunsaturated fatty acids, phospholipids and endogenous antioxidants) changes. Additionally, both icing conditions led to largely good quality and shelf life times and to the absence of changes in colour properties. It is concluded that flow ice as such, or including the presence of ozone, can be considered as ideal strategy to be employed as slaughtering and storage system during the commercialisation of the actual farmed species. The ozone presence has shown some profitable effects as leading to an extended shelf life time by quality retention of several sensory parameters; in contrast, some negligible negative effects could be observed on the secondary and tertiary lipid oxidation development. However, the oxidation values reached by individuals kept under OFI conditions cannot be considered as particularly high.     

Cellular mechanisms of intestine regeneration in the sea cucumber, Holothuria glaberrima Selenka (Holothuroidea:Echinodermata)

Echinoderms are the deuterostome group with the most striking capacity to regenerate lost body parts. In particular, members of the class Holothuroidea are able to regenerate most of their internal organs following a typical evisceration process. Such formation of new viscera in an adult organism provides a unique model to study the process of organogenesis. We have studied this process in the sea cucumber Holothuria glabberrima by describing the spatial and temporal pattern of cellular events that occur during intestine regeneration following chemically induced evisceration. Regeneration begins as a thickening of the mesenteries that supported the autotomized organs to the body wall. The mesenterial thickening consists of tissues where most of the cellular populations found in the normal intestine are already present. However, the cell numbers differ, particularly those of hemocytes and amoebocytes, suggesting that some of these cells play an important role in the formation of the solid rod of hypertrophic mesentery that characterizes the intestinal primordia. The appearance of the luminal epithelium, together with the formation of the lumen, occurs during the second week of regeneration by proliferation and extensive migration of cells from the esophagus and cloacal ends into the thickenings. At this stage all tissue layers are present, but it takes an additional week for them to exhibit the proportions typical of the normal organ. Cell division, as determined by BrdU labeling, mainly occurs in the coelomic epithelia of the hypertrophic mesentery and in the regenerating luminal epithelium. Our study provides evidence that the process of new organ formation in holothurians can be described as an intermediate process showing characteristics of both epimorphic and morphallactic phenomena.     

Changes in free amino acids content in albacore (Thunnus alalunga) muscle during thermal processing

Summary The effects of cooking and sterilization at several temperatures on the free amino acids (FAA) content in albacore (Thunnus alalunga) muscle were studied during the processing of canned tuna. FAAs were derivatized witho-phtalaldehyde, separated on a C18 column by HPLC and detected by both fluorescence and ultra-violet detectors. After cooking the loss of FAAs was not significant. However, in the final product sterilized at 115 °C and 110 °C (throughout the whole process) there were significant losses with regard to the start material, but not at 118 °C (all temperatures leading to the same lethal F-value). The influence of the thermal process time at 115 °C was evaluated for 60 and 100 min. Significant losses were found between both canned products (25%) and between the raw fish and the final product (12% and 34%, process time 60 and 100 min, respectively). The determination of the content of FAA present in canned albacore may be a useful indication of the severity of the thermal processing.

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Veränderung im Gehalt an freien Aminosäuren in Thunfischmuskel (Tunnus alalunga) während der Wärmebehandlung

Zusammenfassung Die Wirkung des Kochens und Sterilisierens bei verschiedenen Temperaturen auf den Gehalt an freien Aminosäuren (FAA) im Thunfischmuskel (Thunnus alalunga) wurde während der Herstellung von Thunfischkonserven untersucht. Die freien Aminosäuren wurden mito-Phtalaldehyd derivatisiert, auf einer C-18-Kolonne mit HPLC abgetrennt und durch Fluorescenz und UV-Detektoren nachgewiesen. Nach dem Kochen war der Verlust an FAA nicht signifikant, jedoch in dem bei 110° und 115 °C sterilisierten Endprodukt ergaben sich signifikante Verluste bezogen auf das Ausgangsmaterial, aber nicht auf das bei 118 °C erhitzte; alle Erhitzungstemperaturen führen zu demselben letalen F-Wert. Der Zeiteinfluß der Erhitzung bei 115 °C wurde bei 60 und 100 min bewertet. Signifikante Verluste sind bei beiden Dosenkonserven aufgetreten (25%) und zwischen diesen und dem Rohfisch ( 12% und 34%) bei einer Erhitzungszeit von 60 und 100 min). Die Bestimmung des FAA-Gehalts in Thunfischkonserven kann für den Nachweis der Einwandfreiheit des thermischen Prozesses sehr nützlich sein.

     

Event-driven,pattern-based methodology for cost-effective development of standardized personal health devices

Experiences applying standards in personal health devices (PHDs) show an inherent trade-off between interoperability and costs (in terms of processing load and development time). Therefore, reducing hardware and software costs as well as time-to-market is crucial for standards adoption. The ISO/IEEE11073 PHD family of standards (also referred to as X73PHD) provides interoperable communication between PHDs and aggregators. Nevertheless, the responsibility of achieving inexpensive implementations of X73PHD in limited resource microcontrollers falls directly on the developer. Hence, the authors previously presented a methodology based on patterns to implement X73-compliant PHDs into devices with low-voltage low-power constraints. That version was based on multitasking, which required additional features and resources. This paper therefore presents an event-driven evolution of the patterns-based methodology for cost-effective development of standardized PHDs. The results of comparing between the two versions showed that the mean values of decrease in memory consumption and cycles of latency are 11.59% and 45.95%, respectively. In addition, several enhancements in terms of cost-effectiveness and development time can be derived from the new version of the methodology. Therefore, the new approach could help in producing cost-effective X73-compliant PHDs, which in turn could foster the adoption of standards.     

Effect of advanced chilling methods on lipid damage during sardine (Sardina pilchardus) storage

Slurry ice is a biphasic system consisting of small spherical ice crystals surrounded by seawater at subzero temperature. Its effect on lipid damage (hydrolysis and oxidation) was evaluated during the chilled storage of a fatty fish species, sardine (Sardina pilchardus). Slurry ice treatment was checked alone and in combination with ozone and compared to traditional flake icing during a 22‐day storage. Different lipid damage indices (free fatty acids, FFA; peroxide value, PV; thiobarbituric acid index, TBA‐i; fluorescent compounds, FR) were checked and compared to sensory assessment and nucleotide degradation (K value). According to lipid hydrolysis (FFA) and oxidation (PV and FR) developments, slurry ice showed an inhibitory effect (p <0.05) on lipid damage during storage, as well as an inhibition of nucleotide autolytic degradation. Ozonised slurry ice did not provide differences (p >0.05) from slurry ice alone when considering lipid hydrolysis, nucleotide degradation and some lipid oxidation indices (PV and FR), although a higher (p <0.05) TBA‐i was observed at day 22 of storage when compared to flake ice and slurry ice treatments. However, a lower (p <0.05) fluorescence development was observed for fish treated under ozonised slurry ice when compared to traditionally iced fish. Sensory assessment showed a higher shelf life for fish samples treated under ozonised slurry ice than for their counterparts under slurry ice (15 d versus 12 d), while flake icing led to a far shorter shelf life (5 d). According to sensory and biochemical (lipid matter and nucleotide) analysis, slurry ice has proved to be a promising technology for damage inhibition and quality retention in a fatty fish species such as sardine. Ozonised slurry ice was also shown to be useful, since a longer shelf life was obtained in the present experiment and a pro‐oxidant effect of ozone on sardine lipids was not proved.     

Biochemical,functional, and histochemical effects of essential fatty acid deficiency in rat kidney

The present study was designed to examine the effects of EFA deficiency (EFAD) on biochemical, functional, and structural aspects of the kidney in growing and adult rats fed a normal or EFAD diet for 9 wk after weaning. Food and fluid intake (FI), urine volume, and Na⁺ and K⁺ excretions were measured weekly from weeks 4 to 8 by placing the rats in individual metabolic cages for 24 h. At week 9, Li⁺ and a 5% water load, respectively, were administered at 14 and 1.5 h prior to glomerular and proximal tubular function studies, as assessed by 3-h creatinine (C_Cr) and Li⁺ (C_Li+) clearances. Hematocrit and urine volume; serum and urine [Cr], [Li⁺], [Na⁺], and [K⁺]; and renal FA distribution were also measured. Data [corrected to 100 g/body weight (bw) and presented as means ±SEM] were significant, at P<-0.05. Despite a similar ingestion of solids from weeks 4 to 7 (weeks 7 to 10 of life), the rats on the EFAD diet showed a decreased body weight from week 5. From weeks 4 to 8, Fl and urine volume were similar for both groups, but the Fl increased at week 6 in the EFAD group; 24-h Na⁺ and K⁺ excretions were similar at all weeks, except for an increase in the EFAD group for both ions at week 7. In the EFAD group, C_Cr and C_Li+ decreased by 27 and 56.3%, respectively (385.7±33.4 vs. 280±21.1, and 21.0±2.1 vs. 9.2±1.1 μL/min/100 g; n=9 vs. 10), the latter result suggesting increased proximal reabsorption. The 3-h Na⁺ and K⁺ excretions were similar, but the Li⁺ decreased (0.78±0.06×10⁻² vs. 0.32±0.03×10⁻² μeq/min/100 g) in the EFAD group, giving additional support to the suggestion. Renal structure was normal and similar for both groups, but the EFAD group showed a more prominent proximal tubule brush border, together with heavier periodic acid-Schiff staining in all specimens from weeks 5 to 9. In the EFAD group, FA of the n−9 and n−7 series were higher, but most of the n−6 series were lower as a percentage of total lipids in the medulla and cortex. Medullary levels of 20∶4n−6 were maintained, 22∶4n−6 declined twice, arachidonic acid was maintained, and 20∶5n−3 was lower. The EFAD diet affected glomerular function, proximal tubular structure and function, and FA distribution in the rat kidney.