Gene transfer of herpes simplex virus type I thymidine kinase gene as a drug sensitivity gene into human lung cancer cell lines using retroviral vectors

A number of packaging materials are being used not only to contain food during distribution but also to serve as the cooking container. The higher temperatures that these materials reach led the US Food and Drug Administration (FDA) to issue an intent to publish new regulations in 1989. The food and packaging industries responded by conducting extensive research and submitting the results to FDA. The methods used and results obtained are discussed. Most of the data were focused on microwave susceptors and the volatile compounds generated. One project showed that for a specific product, popcorn, there was no transfer into the food. Work is continuing to validate methods to test for non-volatile compounds. In addition to susceptors, various paper and plastic materials are used in dual ovenable (microwave and conventional ovens) applications. Most of the research on these materials has investigated the food contact temperatures on testing for migrants. An update on the current regulatory status of packaging materials intended for high temperature use in the US is discussed.     

Measurement of styrene oxide in polystyrenes, estimation of migration to foods, and reaction kinetics and products in food simulants

The concentration of styrene-7,8-oxide has been measured in nine base resins and 16 samples of polystyrene articles intended for food contact. The epoxide was not detected in the resins (limit of detection 0.5 mg/kg) but was found in 11 of the 16 packaging samples at up to 2.9 mg/kg. Assuming that the propensity of styrene oxide to migrate is the same as styrene monomer, and using existing survey data for styrene monomer in packaging and foods, the migration levels expected for styrene oxide were calculated. Estimates were from 0.002 to 0.15 microgram/kg styrene oxide in foods. The stability of styrene oxide in the four standard EU food simulants was studied at 40, 100, 150 and 175 degrees C, to establish the transformation products to be expected following migration testing. The half-life at 40 degrees C in distilled water, 15% aqueous ethanol, 3% aqueous acetic acid and olive oil was 15, 23, < 1, > 2000 hr, respectively. The principal product was the diol from hydrolysis of the epoxide group. Ring opening in aqueous ethanol simulant gave the diol and also the glycol monoethyl ether. It is concluded that this instability of styrene oxide will reduce concentrations in foods, from an already low migration level to even lower levels with the formation of hydrolysis products that are less toxic than the parent epoxide.     

Comparison of microwave oven and convection oven for acid hydrolysis of dietary fiber polysaccharides

Hydrolysis of dietary fiber polysaccharides (DFP) is an integral part of any enzymatic-chemical method for dietary fiber analysis. Residues obtained after enzyme treatments of fiber-containing foods are usually suspended in 12 M sulfuric acid and kept at or slightly above ambient temperature for at least 1 h, and then the mixtures are diluted with deionized water to a final concentration of 1 M or 2 M acid, followed by heating at 100 degrees C in a water bath or convection oven for 1 or 2 h. Under these hydrolytic conditions, some degradation of the released monosaccharides generally takes place over the duration of hydrolysis. We investigated the feasibility of using microwave energy as a heat source to reduce time and minimize degradation. Preliminary tests were done on the well-characterized soy polysaccharide Fibrim. With a microwave digestion system equipped with temperature and pressure monitors and control lines, optimum settings of power (5%, 75%), time (up to 3 min and 30 s), temperature (35 degrees-55 degrees C), and pressure (45-65 psi) were determined for different foods depending on the residue weight and volume of acid. Results were comparable for microwave oven and convection oven hydrolysis of DFP from 5 foods with good correlations for neutral sugar values; r2 = 0.997 for arabinose, 0.925 for galactose, 0.981 for glucose, 0.969 for mannose, and 0.990 for xylose.     

Specific migration of di-(2-ethylhexyl)adipate (DEHA) from plasticized PVC film: results from an enforcement campaign

A control campaign on the correct labelling of plasticized PVC film according to current legislation on food contact materials has been performed. Analytical methods based on the isotope dilution technique were developed. For enforcement purposes, the films were exposed to the official food simulant, olive oil, followed by clean-up using size exclusion chromatography and final determination of di-(2-ethylhexyl) adipate (DEHA) by combined capillary gas chromatography and mass spectrometry (GC-MS). In the initial screening, the samples were exposed to the alternative food simulant, isooctane, and DEHA could be determined by GC-MS without further clean-up. A good consistency between results from the two different methods was obtained. During the campaign, 49 samples of PVC films, the majority intended for use in retail shops, were sampled from importers and wholesalers by the Municipal Food Control Units. Initially, all films were screened for the migration into isooctane (exposed 2 h at 40 degrees C) of DEHA and other potentially present low molecular weight plasticizers using full scanning mass spectrometry. Films showing a substantial migration of DEHA were further tested with olive oil according to the declared field of application (exposed for 10 days at 40 degrees C). In 47 of the 49 films the migrate contained a substantial amount of DEHA. In 46 films the migration exceeded the specific migration limit of 3 mg/dm2 after use of the relevant reduction factor given in legislation. However, because of the general uncertainty of the analytical method and because the variation in the thickness of the films was calculated to be 1 mg/dm2, the action limit in this campaign was 4 mg/cm2. A migration higher than this action limit was found in 42 films (89% of the samples) and these films were deemed to be illegal according to their present declared field of application as given by their labelling. In a few cases, some migration of the plasticizer di-n-butyl phthalate was seen.     

微波法快速测定钼酸铵中的水分

采用微波加热法对钼酸铵水分含量进行了测定。探讨了加热时间、微波功率和物料重量对水分测定的影响，并和传统烘箱测定进行了对比。     

一水硬铝石矿-氢氧化钠体系微波焙烧相变规律

以饱和氢氧化钠溶液为添加剂,利用微波加热对一水硬铝石矿进行焙烧处理.考察微波焙烧温度和氢氧化钠添加量对一水硬铝石矿-氢氧化钠体系相变规律的影响,并对微波加热和常规加热得出的焙烧产物做物相结构的比较.利用X射线衍射分析和扫描电子显微镜技术对熟料的物相结构和微观形貌进行分析.结果表明微波加热促进氢氧化钠快速并充分的与一水硬铝石矿反应.与常规加热相比,微波加热在更低的温度下能生成更多铝酸钠物相.微波加热后的熟料疏松多孔,有利于后续溶出处理.      

The impact of dietary fats, photoperiod, temperature and season on morphological variables, torpor patterns, and brown adipose tissue fatty acid composition of hamsters, Phodopus sungorus

We investigated how dietary fats and oils of different fatty acid composition influence the seasonal change of body mass, fur colour, testes size and torpor in Djungarian hamsters, Phodopus sungorus, maintained from autumn to winter under different photoperiods and temperature regimes. Dietary fatty acids influenced the occurrence of spontaneous torpor (food and water ad libitum) in P. sungorus maintained at 18 degrees C under natural and artificial short photoperiods. Torpor was most pronounced in individuals on a diet containing 10% safflower oil (rich in polyunsaturated fatty acids), intermediate in individuals on a diet containing 10% olive oil (rich in monounsaturated fatty acids) and least pronounced in individuals on a diet containing 10% coconut fat (rich in saturated fatty acids). Torpor in P. sungorus on chow containing no added fat or oil was intermediate between those on coconut fat and olive oil. Dietary fatty acids had little effect on torpor in animals maintained at 23 degrees C. Body mass, fur colour and testes size were also little affected by dietary fatty acids. The fatty acid composition of brown fat from hamsters maintained at 18 degrees C and under natural photoperiod strongly reflected that of the dietary fatty acids. Our study suggests that the seasonal change of body mass, fur colour and testes size are not significantly affected by dietary fatty acids. However, dietary fats influence the occurrence of torpor in individuals maintained at low temperatures and that have been photoperiodically primed for the display of torpor.     

Alternative test methods to control the compliance of polyolefin food packaging materials with the European Union regulation: the case of aromatic antioxidants and of bis(ethanolamine) antistatics based on 1H-NMR and UV-visible spectrophotometry

In order to decide whether a plastic food packaging material complies with the European Communities (EC) regulation on migration, a quick analysis of two functional classes of plastics additives (aromatic antioxidants and antistatic agents) from polyolefin materials by 1H-NMR and UV-visible spectrophotometry is presented. The scope of spectroscopic methods for alternative and migration tests is presented. 1H-NMR can be used in several ways, from a simple fingerprint of the potential migrants to an identification procedure. Extraction is optimized using UV spectrophotometry. Optimization relies on extraction kinetics, which include the demonstration that extraction is more severe than migration. Only a few hours are required to conclude whether a material complies with the regulation. The specific migration limits are expressed as specific absorbance limit values, alpha. These data can be annexed by food industries to specifications of a plastic packaging material.     

Survival and growth of Campylobacter jejuni after artificial inoculation onto chicken skin as a function of temperature and packaging conditions

Campylobacter jejuni is one of the major causes of food poisoning in humans. C. jejuni is also widespread in food animals, and meat and meat products derived from food animals are the most common vector of bacterial transmission to humans. To determine the role of packing and storage conditions on the replication of C. jejuni on chicken, the virulent strain C. jejuni 81116 was artificially inoculated onto chicken skin pieces (1 cm2) and stored at different temperatures and under various packaging conditions. C. jejuni 81116 remained viable at -20 and -70 degrees C and was able to replicate at 4 degrees C and at ambient room temperature. C. jejuni 81116 was also inoculated onto chicken skin and subjected to repeated freeze thawing and the viability of the inoculum was quantified. C. jejuni 81116 could withstand repeated freeze thawing similar to that which may occur in the domestic home. Under all freezing conditions, C. jejuni 81116 retained a high level of viability and quickly replicated to levels which exceeded Australian food authorities' permitted bacteria level on raw food products after the sample was thawed.     

On the variability of cross-sectional dimensions and torsional properties of rectangular nickel-titanium arch wires

BACKGROUND: Alterations in mouth temperature may lead to changes in the force exerted by an activated superelastic wire. It has been assumed that variations in archwire stiffness associated with short-term cooling or heating are transient. This investigation studied the effect of short-term cooling or heating on the bending force exerted by nickel-titanium archwire. MATERIAL AND METHODS: Six rectangular superelastic wires and one conventional nickel-titanium wire were tested in bending at 37 degrees C. The test specimens were deflected 0.5 mm, and the bending force was measured continually. The activated specimens were subjected to cold (10 degrees C) or hot (80 degrees C) water under constant deflection, simulating an inserted archwire that is subjected to cold or hot drinks or food during a meal. RESULTS: The conventional nickel-titanium wire was marginally affected by brief cooling or heating. In contrast, some of the superelastic wires were strongly affected by short-time application of cold or hot water. Whereas the effect of brief heating disappeared quickly, some wires continued to exert sub-baseline bending forces (up to 32% less) after short-time application of cold water and showed little or no tendencies toward increase even after 30 minutes of postexposure restitution (up to 43% less). CONCLUSIONS: Short-term exposures to hot liquid increased the bending force exerted for a given deflection transiently. The effect of short-term exposures to cold liquid was not always transient; the bending force remained sub-baseline for a number of the thermosensitive wires tested for a prolonged time.     

Evaluation of Strength Properties of Polypropylene-Based Polymers in Simulated Landfill and Oven Conditions

Polymeric films and fibers are used extensively in industrial and personal products. Many of these products are intended to be disposable and, after initial use, are disposed in landfills that are increasingly expensive and limited. Proprietary additives are being promoted to enhance the biodegradation of polypropylene (PP) and related materials. A test was run on samples of diapers containing PP in simulated landfills and in convection ovens over a period of 52?weeks. Samples in the oven treatment lost all strength properties in less than 27?weeks. Back sheet and cuff samples in the landfill lost insignificant (P<0.05) strength under landfill conditions over 52?weeks. Statistics show significant differences (P<0.05) in strength and sample percent elongation during testing for time, temperature, and time-temperature interactions for both the oven and landfill tests. The study led to the conclusion that the polypropylene additive was efficacious for programmable destruction in an oxidative environment but not efficacious in an anaerobic environment.     

Degradation of malathion in thermally generated aerosols

The degradation of malathion, undiluted and diluted with No. 2 fuel oil, in thermally generated aerosol clouds was examined at selected temperatures ranging from 121 to 566 degrees C. Undiluted malathion residues decreased from 1.76 to 0.21 micrograms/ml over this range of temperatures. Malathion diluted with fuel oil decreased from 0.14 to 0.02 microgram/ml as the temperature was increased 288 to 510 degrees C.     

Human papillomavirus as an etiological factor in cervical cancer: significance for health care practice

The migration of substances from rubber packaging materials into drug products can be significant with certain packaging materials in contact with organic solvent systems. Recommendations for testing drug products for leachables are continually evolving to address new developments. Testing packaging materials using simulated solvents is not always an acceptable protocol for the pharmaceutical industry. We describe a rational strategy for evaluation of the drug product for packaging extractables. A profile of the extractables from rubber packaging materials was made with a range of organic solvents and stress conditions to provide information on substances to target in the drug product. The drug product was evaluated to determine if the matrix would cause interferences that might inhibit detection of the found extractables. Analytical methods were selected based on these findings. The procedures were validated according to FDA guidelines. A stability program using time and storage conditions as variables provided information for acceptance criteria. This same strategy can be used on other types of pharmaceuticals and packaging materials.     

安钢7号焦炉智能自适应加热控制系统

为了提高焦炉自动化加热水平,稳定焦炭质量,提出了焦炉智能自适应加热管理的自动控制方案,通过在安钢焦化厂7号焦炉上的应用,较好地解决了长期以来由传统控制方案带来的滞后导致焦炉炉温波动大、耗热量高的弊端,取得了较为明显的经济效益和社会效益。     

Effect of conventional and microwave sintering on the properties of yttria alumina garnet-dispersed austenitic stainless steel

The current study examines the effect of heating mode, temperature, and varying yttria alumina garnet (YAG) addition (5 and 10 wt pct) on the densification and properties of austenitic (316L) stainless steel. The straight 316L stainless steel and 316L-YAG composites were heated in a radiatively heated (conventional) and 2.45 GHz microwave sintering furnace. The compacts were consolidated through solid state as well as supersolidus sintering at 1200 °C and 1400 °C, respectively. Both 316L and 316L-YAG compacts couple with microwaves and heat to the sintering temperature rapidly (∼45 °C/min). The overall processing time was reduced by about 90 pct through microwave sintering. As compared to conventional sintering, compacts sintered in microwaves exhibit higher densification and finer microstructure but no corresponding improvement in mechanical properties and wear resistance. This has been correlated to elongated, irregular pore structure in microwave-sintered compacts.     

An experimental study of conductive heating using a concentric double-electrode applicator

With hyperthermia for treatment of superficial tumors in mind, a prototype applicator with two electrodes arranged concentrically on a disk was designed for efficient local heating, and a basic heating test was carried out. Frequencies as low as 200 kHz were used in order to simplify the configuration of the power device. The applicator consists of two electrodes, a circular inner electrode and another looped outer electrode, arranged concentrically. Water was passed through the applicator as a cooling mechanism; it was placed in direct contact with the target tissue to be heated and then charged with electricity. In the heating test using a phantom, oval hot spots were noted below the inner electrode. Using cooling water at 3 degrees C and 8.2 W, an isothermal line of 45 degrees C was located at a 5-mm radius circle around the central axis with 9 mm depth. A similar temperature distribution map was obtained in heating tests on the thigh muscle of a mongrel adult dog. The temperature distribution maps obtained from these tests corresponded closely with the results of theoretical analysis carried out according to the finite-element method. Since a comparatively low frequency was employed for this applicator the power device was simplified, which made adequate heating possible with low electric power. The temperature distribution map indicated that efficient local heating of superficial tumors could be achieved.     

微波加热与常规加热高碳铬铁粉固相脱碳效果的研究

研究了900~1200℃ 0~60 min微波加热和普通马弗炉加热两种方式,用固体脱碳剂碳酸钙(96.04%CaCO₃)对高碳铬铁粉(/%:55.79Cr,32.76Fe,8.16C,2.34Si)脱碳的影响。结果表明,试验条件下,微波加热高碳铬铁粉的固相脱碳效果较常规加热明显,而且常规加热时物料氧化程度严重,微波加热混合物料至1100℃ 60 min,铬铁粉脱碳率为79.04%,获得较好脱碳效果的同时,避免了物料的过分氧化。     

电焊条用钛铁矿的介电特性及微波加热特征

电焊条用含钛原料的介电特性研究对于拓宽焊条制造原料来源和发展微波加热制备还原钛铁矿具有重要的指导意义.采用同轴探头反射法测定了钛铁矿粉末（含TiO237%～47%）在2.45 GHz频率下和20～80℃之间的介电特性,并测定钛铁矿在微波场下的温升特性.研究结果表明：钛铁矿的介电常数和介电损耗因子及损耗角正切随着温度的上升而增加,介电特性总体随着含钛品位增高逐渐增强.钛铁矿的穿透深度在40～80℃之间随温度增加逐渐降低,微波加热钛铁矿的最佳物料厚度为3～6 cm.微波场下钛铁矿的升温曲线表明温度和微波加热时间具有一个非线性关系.     

Hyperbaric oxygen inhibits the growth of cultured rabbit lens epithelial cells without affecting glutathione level

The influence of electron beam irradiation on migrational behaviour of additives present in food packaging material was studied. The migration experiments were carried out on irradiated and non-irradiated polypropylene pouches containing aqueous food simulating liquids (FSL) for 10 days at 40 degrees C. The controls were irradiated and non-irradiated pouches without FSL contact. After the contact period, the polypropylene and the FSL were analysed. A comparison between the results obtained by the two analyses showed the migration of three products of antioxidant degradation from the polypropylene into the FSL, and a partial decomposition of these migrants in the FSL.     

Changes in the quality parameters of virgin olive oil from the Lower Aragon area of Teruel during the storage

Virgin olive oil from the Lower Aragon area, despite its excellent alimentary qualities, is a product which is sensitive to high temperatures and sunlight. In this work, during a 10 months storage period, a study was made of the variation in acidity, the index of peroxides, K270 and alpha-tocopherol in two olive oils, one of which was made from fresh olives by means of the traditional oil mill methods, a discontinuous method, and the other oil was obtained from pre-fermented olives by means of the modern centrifugation method, or the continuous method. These parameters were measured in both types of oil, in samples stored at room temperature (variable) and others stored at a constant temperature (20 degrees C + 1 degree C). A sub-sample of each of these was stored in the dark, and another in the presence of light. The variation of the parameters allows us to see the variation which takes place with regard to the nutritive properties of the oil ashen this is stored.