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Fresh-cut watermelon is increasingly popular among consumers but challenges remain in keeping its eating quality. Processing removes the protective skin layer that usually provides a buffer for internal fruit tissues against environmental stresses and maintains elevated CO 2 and lowered O 2 gas levels. Low temperatures are used to slow microbial growth and prolong shelf-life of cut fruit by reducing oxidative, enzymatic and metabolic reactions that lead to accelerated senescence. However, little information is available on the interactive effects of the initial whole fruit temperature with subsequent fresh-cut product storage temperature on the consequences for shelf-life of fresh-cut watermelons. Whole watermelons were stored for 21 h at 4, 21 or 30°C, before being sanitised, cut into cubes, packaged and stored at 4 or 7°C until analysed. Interaction between the factors of storage temperature before and after cutting led to juice drip pH and soluble solid content changes. Lower whole-fruit temperature and lower storage temperature of fresh-cuts significantly reduced O 2 consumption and CO 2 production rates. Headspace ethylene levels were also reduced by lower fresh-cut watermelon storage temperatures. Preliminary trials show fruit aroma levels at day 5 scored higher when whole watermelons were stored at 21°C than either 4 or 30°C. In a second experiment, watermelon cubes were processed together with honeydew, rockmelon, pineapple and apple and then sealed individually or as a fruit-mix and stored at 4°C until analysed. Ethylene levels as high as 95 ppm were measured in the headspace of fruit-mix samples, with increased water soaking appearance of watermelon cubes. Our results demonstrate the need to consider the storage temperature of both whole and fresh-cut watermelons to extend shelf-life by controlling physiological aspects such as respiration. There is also potential for selecting fruits in fresh-cut fruit-mixes that minimise ethylene production to lower the impacts on fresh-cut watermelon shelf-life.

We present a graphene oxide (GO) film as a superior substrate for the controlled anchoring and micropatterning of a blinking silver nanocluster–nanoparticle hybrid. Localised laser reduction of the GO film in the presence of AgNO3 solution results in the controlled deposition of Ag nanoparticles (NPs) onto the reduced GO (rGO) film. Upon irradiation by blue light, some of these NPs turn into nanoblinkers (AgO/Agn hybrid) exhibiting dynamic tricolored fluorescence intermittency. Via the scanning laser beam, a wide variety of micropatterns with a high density of nanoblinkers are achieved on the GO/rGO film. Most remarkably, the nanoblinkers formed on GO/rGO remain vibrant even after a period of 1 year, unlike other substrates (CNT, SiO2/Si wafer) studied. Furthermore, both the micro-patterns and tricoloured blinking behaviour are preserved upon their transfer from the GO film onto other surfaces such as glass and a PDMS film. The hybrid material can also be used to detect Rhodamine B dye where the fluorescing colour of the Ag nanoblinkers changes upon interaction with the dye. The shade of fluorescence and the blinking rate of the nanoblinkers are highly dependent on the duration of interaction between the nanoblinkers and the Rhodamine B molecules.

This paper presents the experimental effects of lubricant with nanodiamond particles in sliding friction. In order to improve the performance of lubricants many additives are used, such as MoS2, cadmium chloride, indium, sulfides, and phosphides. These additives are harmful to human health and to the environment, so alternatives are necessary. One such alternative is nanodiamond powder, which has a large surface area. In order to investigate the effect of nanodiamonds in lubricants under sliding friction, they are dispersed in the lubricant at a variety of concentrations (0 wt%, 0.1 wt%, 0.3 wt%, 0.5 wt%, and 1 wt%) using the matrix synthesis method. Friction and wear tests are performed according to the ASTM G99 method using a pin-on-disc tester at room temperature. The specimens used in this experiment are AISI 52100 ball bearings and AISI 1020 steel discs. During the test, lubricant mixed with nanodiamond is supplied constantly to keep the two bodies separated by a lubricant film. To maintain boundary lubrication, the speed is set to 0.18 m/s and a load of 294 N is applied to the disc through the pin. Results are recorded by using workbench software over the test duration of 10 minutes. Experimental results show that when the concentration of nanodiamond increases, the coefficient of friction decreases. However, above a nanodiamond concentration of 0.5 wt%, both the coefficient of friction and wear volume increase. From this experiment, the optimum concentration of nanodiamond showing a minimum coefficient of friction of 0.09 and minimum wear volume of 0.82 nm2 was 0.5 wt%.

Structural development in cast films of poly(2,5-di-n-octyloxy-1,4-phenylenevinylene) (DO-PPV) upon heat treatment was studied by means of polarized light microscopy, X-ray diffraction, ultraviolet−visible spectroscopy, and photoluminescence spectroscopy as well as scanning and transmission electron microscopy. Results indicated the dominance of a lamellar phase of biaxially refringent nematic-like texture upon short-term heat treatments at elevated temperatures (Ta) between 160 and 240 °C. A further increase in Ta results in dissipation of the mesomorphic order near the isotropization temperature Ti = ca. 300 °C. This lamellar phase, 1.8 nm in layer spacing at room temperature, typically consists of beads or grains approximately 10−20 nm in diameter that agglomerate into wormlike features in the absence of external stress. Mechanical shear right after high-temperature annealing results in disintegration of worms formed in the tranquil state; the constituent beads nevertheless reagglomerate into new worml...

To investigate influences of pulsed electric field (PEF) on bovine IgG immunoactivity, soymilk enriched with hyperimmunized dairy milk protein concentrate was subjected to PEF and thermal treatments. Thermal treatment at 78.8 °C for 120 s inactivated 5.1 logs in natural flora and resulted in 86% decrease in IgG activity PEF at 41 kV/cm for 54 μS inactivated 5.3 logs of natural flora and resulted in no significant change (P > 0.05) in bovine IgG activity. Specific antigen-binding activity of bovine IgG against Salmonella enteritidis showed parallel correlation with the measurement of IgG concentration. No further significant change in IgG immunoactivity was observed during a 10-wk storage at 4°C in PEF-, thermally-, or un-treated samples.

Cadmium (Cd) in the human diet still constitutes a potential chronic hazard to health. Cd accumulates in the kidneys and harmful effects are likely to occur when its concentration in the renal cortex exceeds 200 μg /g fresh weight (Fassett, 1980). Suzuki et al. (1988) and Kawada et al. (1998) reviewed the Cd concentrations in the human renal cortex which ranges from 10 to 30 μg/g wet weight for Europeans and Americans, while it is 65 to 115 μg /g wet weight for Japanese who have always had the highest renal Cd levels in the world. The amount of Cd accumulated in the kidneys is a function of age and/or daily Cd intake, the latter of which comes mostly from foods and beverages. Cd in drinking water and in the atmosphere contribute very little to such accumulation (Yokohashi 1973). Consequently, the monitoring of levels of Cd in various foods is essential for the better understanding of Cd accumulations in the human body. As the pollution levels of Cd have decreased as a result of measures and regulations against hazardous substances in almost every country, the background survey of Cd has become increasingly important.

Oral administration of Prudhoe Bay crude or Hibernia crude to nestling herring gulls increased the hepatic cytochrome P-450 content 4-fold. Concomitantly, there was an increase in various mixed-function oxidase and phase II enzyme activities. 7-Ethoxyresorufin O-deethylase was elevated 19-fold, benzo(a)pyrene 3-hydroxylase 6-fold, aniline hydroxylase 3-fold, and aminopyrine N-demethylase and uridine diphosphate glucuronyl transferase 2-fold. There was no change in reduced glutathione S-transferase activity. Renal mixed-function oxidase activities were also elevated. Herring gull livers contained very low levels of DT-diaphorase activity which was inducible 3- to 5-fold by oil administration.

Application of a Prudhoe Bay crude oil (PBCO) to the backs of mice caused a rapid induction of epidermal ornithine decar☐ylase (ODC). A maximum induction of over 60-fold was seen at 6 hr after application of 50 μl of PBCO. Concurrently, epidermal putrescine levels were elevated 4.7-fold over controls. Intraperitoneal administration of PBCO led to a 15–20-fold increase in hepatic ODC activity but to a 45% decrease in the renal enzyme activity. Maximum induction of ODC was seen at 12 hr following the administration of 4 ml/kg body wt of PBCO. Hepatic putrescine levels were elevated 34-fold over controls. Pretreatment of mice with the protein synthesis inhibitor cycloheximide abolished both epidermal and hepatic ODC induction.

Heinz body hemolytic anemia developed in Herring Gull (Larus argentatus) nestlings given oral doses of 10 ml of Prudhoe Bay crude oil per kilogram of body weight per day for 5 days. Associated disturbances in red blood cells were increased amounts of reduced glutathione (GSH), peroxidation of membrane lipids, an increase in membrane permeability, and a decrease in the oxygen-carrying capacity of cyanomethemoglobin-convertible hemoglobin. Among groups of gulls given different cumulative doses of oil over a 6-day period, significant covariance with dose and dependence on dose was demonstrated for packed cell volume, hemoglobin, and red cell GSH. Rapid defecation of oil by gulls indicated that the effective dose was substantially less than the administered dose. Pronounced damage to red cells occurred in some birds administered oil for only 2 days. These data imply that the toxic effects of ingested oil may contribute significantly to the morbidity and mortality of oil-contaminated birds.

Microliter quantities of a Prudhoe Bay crude oil (PBCO) applied to the shell of fertile chick eggs during various stages of development induced cytochrome P-450 levels and mixed-function oxidase activities within the liver of the embryo. PBCO (5 microliter) applied on Day 11 of incubation was found to maximally induce within 24 hr embryo hepatic cytochrome P-450 levels (fourfold), naphthalene hydroxylase (sixfold), benzo[a]pyrene 3-hydroxylase (14-fold), and 7-ethoxyresorufin O-deethylase (24-fold). Glutathione S-transferase was not induced. Crude oils are known to be highly toxic to avian embryos, especially during the early stages of development. The LD50 of PBCO and Hibernia crude oil applied to the egg shell on Day 8 of incubation was found to be 1.3 and 2.2 microliter, respectively. Mixed-function oxidase-dependent metabolism of crude oil components may be required for toxicity since administration of 20 micrograms of disulfiram in dioxane 1 hr prior to application of 1.3 microliter of PBCO reduced embryo mortality from 60 to 20%.