Polymer gels impregnated with gold nanoparticles implemented for measurements of radiation dose enhancement in synchrotron and conventional radiotherapy type beams

Normoxic type polyacrylamide gel (nPAG) dosimeters are established for dose quantification in three-dimensions for radiotherapy and hence represent an adequate dosimeter for quantification of the dose variation due to the existence of the gold nanoparticles (AuNPs) in the target during irradiation. This work compared the degree of polymerisation in gel doped with nanoparticles (nPAG-AuNP) with control gel samples when irradiated by various sources. Samples were irradiated with a synchrotron radiation source of mean energy 125?keV, 80?kV X-ray beams from superficial therapy machine (SXRT), 6?MV X-rays and 6?MeV electron beams from linear accelerator. Analysis of the dose-response relation was used to determine a dose enhancement factor (DEF) of 1.76?±?0.34 and 1.64?±?0.44 obtained for samples irradiated with kilovoltage X-rays energy from synchrotron source and SXRT respectively. Similarly, including AuNPs in gel results in a DEF of approximately 1.37?±?0.35 when irradiated by an electron beam and 1.14?±?0.28 for high energy X-ray beams. The results demonstrate the use of AuNPs embedded in polymer gels for measuring the enhancement of radiation caused by metallic nanoparticles.     

Lipid-altering effects of a dietary supplement tablet containing free plant sterols and stanols in men and women with primary hypercholesterolaemia: a randomized, placebo-controlled crossover trial

This randomized, placebo-controlled, crossover trial assessed the lipid-altering efficacy of a dietary supplement (tablet form) providing 1.8?g/day free (non-esterified) plant sterols and stanols versus placebo for 6 weeks as part of a therapeutic lifestyle changes (TLC) diet in 32 men and women with primary hypercholesterolaemia. Mean?±?SE baseline (end of a 5-week TLC diet lead-in) lipid concentrations (mmol/l) were total cholesterol (TC), 5.88?±?0.08; non-high-density lipoprotein cholesterol (non-HDL-C), 4.71?±?0.09; low-density lipoprotein cholesterol (LDL-C), 4.02?±?0.08; HDL-C, 1.17?±?0.06 and triglycerides (TGs), 1.51?±?0.12. Differences from control in responses (plant sterol/stanol?-?control) were significant (p?相似文献   

A critical body residue approach for predicting persistent bioaccumulative toxicant effects on reproduction and population dynamics of meiobenthic copepods

Critical body residues (CBRs) are the measured tissue toxicant concentrations yielding a median dose-response on a dry-weight or lipid-normalized basis. They facilitate management decisions for species protection using tissue analysis. Population CBR is the mean dose yielding 50% population suppression and was predicted here in Amphiascus tenuiremis for fipronil sulfide (FS) using lifetables and the Leslie matrix. Microplate bioassays (ASTM E-2317-14) produced biomass sufficient for dry mass and lipid-normalized CBR estimates of reproduction (fertility) and population growth suppression. Significant FS toxic effects were delayed naupliar development (at ≥0.10?μg?L(-1)), delayed copepodite development (at 0.85?μg?L(-1)), decreased reproductive success (at ≥ 0.39?μg?L(-1)), and decreased offspring production (at 0.85?μg?L(-1)). A reproductive median effective concentration (EC50) of 0.16?μg?L(-1) (95% CI: 0.12-0.21?μg?L(-1)) corresponded to an adult all-sex CBR and lipid-normalized CBR of 0.38?pg FS?·?μg(-1) dry weight (95% CI: 0.27-0.52?pg FS?·?μg(-1)) or 2.8?pg FS?·?μg(-1) lipid (95% CI: 2.2-3.6?pg FS?·?μg(-1)), respectively. Copepod log bioconcentration factor (BCF)?=?4.11?±?0.2. Leslie matrix projections regressed against internal dose predicted fewer than five gravid females in a population by the third generation at 0.39 and 0.85?μg FS?·?L(-1) (i.e., 9.6-10.2?μg FS?·?μg(-1) lipid), and 50% population suppression at a CBR of 1.6?pg FS?·?μg(-1) lipid. This more integrative population CBR as a management tool would fall 1.75 times below the CBR for the single most sensitive endpoint-fertility rate.     

Dietary supplementation with n-3 PUFA does not promote weight loss when combined with a very-low-energy diet

Obesity is associated with elevated levels of inflammation and metabolic abnormalities which are linked to CVD. The aim of the present study was to investigate whether long-chain n-3 PUFA (LCn-3PUFA), combined with a very-low-energy diet (VLED), facilitated weight loss and weight maintenance, and improvements in blood lipids and inflammatory mediators. This was a double-blind, randomised, controlled trial with two parallel groups. For 14 weeks, one group consumed 6?×?1?g capsules/d of monounsaturated oil (placebo group, PB), and the other group consumed 6?×?1?g capsules/d of LCn-3PUFA (fish oil group, FO), each comprising 70?mg EPA and 270?mg DHA. Both groups were on VLED for 4 weeks (n 14 PB, n 18 FO), which was then followed by 10 weeks of weight maintenance (n 12 PB, n 17 FO). Fasting blood samples, anthropometric measurements and 3?d food diaries were collected at baseline, at 4 and 14 weeks. A greater-than-2-fold increase occurred in plasma levels of EPA and DHA in the FO group (P?相似文献   

Vapor pressure of three brominated flame retardants determined by using the Knudsen effusion method

Brominated flame retardants (BFRs) have been used in a variety of consumer products in the past four decades. The vapor pressures for three widely used BFRs, that is, tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD), and octabromodiphenyl ethers (octaBDEs) mixtures, were determined using the Knudsen effusion method and compared with those of decabromodiphenyl ether (BDE209). The values measured extrapolated to 298.15?K are 8.47?×?10??, 7.47?×?10?1?, and 2.33?×?10?? Pa, respectively. The enthalpies of sublimation for these BFRs were estimated using the Clausius-Clapeyron equation and are 143.6?±?0.4, 153.7?±?3.1, and 150.8?±?3.2?kJ/mole, respectively. In addition, the enthalpies of fusion and melting temperatures for these BFRs were also measured in the present study.     

Alpha-amylase, α-glucosidase and lipase inhibiting activities of polyphenol-rich extracts from six common bean cultivars of Southern Italy,before and after cooking

Common beans (Phaseolus vulgaris) are a good source of nutrients and phenolic compounds with versatile health benefits. Polyphenol-rich extracts of six ecotypes of P. vulgaris were analysed to determine their phenolic profiles and assayed in vitro for inhibitory effects on digestive enzymes relevant to carbohydrates and lipids metabolism. The extracts inhibited enzyme activities in a dose-dependent manner. IC 50 values ranged from 69?±?1.9 to 126?±?3.2?μg/mL and from 107.01?±?4.5 to 184.20?±?5.7?μg/mL, before and after cooking, for α-amylase, from 39.3?±?4.4 to 74.13?±?6.9?μg/mL and from 51?±?7.7 to 122.1?±?5.2?μg/mL for α-glucosidase and from 63.11?±?7.5 to 103.2?±?5.9?μg/mL and from 92.0?±?6.3 to 128.5?±?7.4?μg/mL for lipase. Results suggest encouraging their consumption, being natural sources of enzyme inhibitors important for type-2 diabetes and obesity prevention/control. Well-monitored in vivo studies would help to establish their beneficial effects, making them worthwhile of further consideration as functional foods.     

Genetic influences on age-related change in total cholesterol,low density lipoprotein-cholesterol and triglyceride levels: Longitudinal apolipoprotein E genotype effects

This study addressed the possible influence of apolipoprotein E (apo E) genotype on age-related changes in total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), and triglyceride (TG) levels in older males. Apo E is a component of LDL, is a ligand for the LDL receptor, and apo E genotype has been consistently associated with variation in mean levels of TC and LDL-C, and also appears to influence TG levels. Using male twins followed longitudinally between mean ages of 48 and 63 years, the change in TC, LDL-C, and TG over time for individuals with the ?3?3 and the ?3?4 genotypes was contrasted. At exam 1 mean TC and LDL-C levels were lower in the ?3?3 group than in the ?3?4 group, but at exam 3 mean TC and LDL-C levels were significantly higher in the ?3?3 group than in the ?3?4 group. The rate of change in TC and LDL-C with age differed significantly between ?3?3 and ?3?4 groups. Results for TG were not statistically significantly. These findings suggest that the apo E genotype effects on risk of coronary artery disease may be age-dependent. This study demonstrates the value of longitudinal studies in refining models for genetic risk factors for disease. © 1994 Wiley-Liss, Inc.     

Practical considerations for reporting surface dose in external beam radiotherapy: a 6?MV X-ray beam study

In this study, we assessed the accuracy of surface doses determined by direct measurement and treatment planning system (TPS) calculations, relative to benchmark Monte Carlo (MC) doses calculated at 70?μm for a 6?MV, 10?×?10?cm clinical radiotherapy beam. In a homogeneous phantom with both open and fixed wedged fields, we found that the relative dose measured with an Attix chamber underestimates the MC calculated surface dose by 2.9?%, while the relative dose measured with EBT2 Gafchromic film overestimates the MC surface dose by 0.9?%. There was a significant over-response of up to 20?% in doses calculated at <2?mm depth with the Eclipse analytic anisotropic algorithm (AAA) compared to corresponding MC doses for an open field. This drops to <2?% at 2?mm depth. In a heterogeneous phantom, EBT2 film overestimates relative dose by up to 3.1?% compared to the MC calculated surface dose. The AAA relative dose calculated in a heterogeneous phantom at 2?mm depth agrees to within 1.5?% with the MC doses calculated at the same depth, but overestimates the MC surface dose (at 70?μm) by up to 2.5?%. Our results suggest that TPS doses evaluated near the surface be reported with a depth that should be at least 2?mm and this should be taken into consideration in the planned target volume for treatments where surface dose is a constraining factor. Our study demonstrates the usefulness of EBT2 film for measuring surface dose: under homogeneous conditions, the effective point of measurement of EBT2 film can be considered equivalent to the clinical skin depth of 70?μm.     

Determination of ²³⁹Pu airborne concentration alpha correction factor for a zinc sulfide detector via ambient ²²²Rn progeny air sampling

This research empirically determined the 23?Pu airborne concentration alpha correction factor for an ADM-300 zinc sulfide detection system via ambient 222Rn progeny air sampling using a RADeCO high volume air sampler. Radon progeny air samples were collected on a four inch glass fiber filter and evaluated on both a high purity germanium detector and the ADMē-300 simultaneously using the three count method. These data were analyzed to obtain a loss fraction in the glass fiber filter for the 21?Bi collected. The 21?Bi response then was used to estimate a loss fraction for 23?Pu. The 23?Pu airborne concentration alpha correction factor for the ADM-300 detection system was found to be 445 ± 47 dpm ft3 cpm?1 m?3 as compared to a previously published correction factor of 500 dpm ft3 cpm?1 m?3.     

Effects of roasting on oil and fatty acid composition of Turkish hazelnut varieties (Corylus avellana L.)

Abstract

A total of 18 natural and roasted hazelnut varieties (namely, Ac?, Cavcava, Çak?ldak, Fo?a, Ham, ?ncekara, Kal?nkara, Kan, Karaf?nd?k, Kargalak, Ku?, Mincane, Palaz, Sivri, Tombul, Uzunmusa, Yass? Badem, and Yuvarlak Badem), grown in the Giresun province of Turkey, were compared for their differences in oil content and fatty acid profiles. The oil content in natural and roasted hazelnut varieties ranged from 57.85% for Kargalak to 68.31% for ?ncekara and from 61.37% for Kargalak to 71.72% for ?ncekara, respectively. A total of 20 fatty acids were identified in oils extracted from different varieties of natural and roasted hazelnuts. Among the identified fatty acids in natural hazelnut oils, 18:1ω9 was the dominant fatty acid (ranging from 77.77 to 86.91%). Roasting had minor influence on the fatty acid profiles. These results suggest that semi-commercial hazelnut varieties are as good source of oils and possess valuable fatty acid profiles as commercial varieties (Tombul, Çak?ldak, Fo?a, Karaf?nd?k, Mincane, Palaz, and Sivri).     

Nutritional quality of fermented defatted soya and flaxseed flours and their effect on texture and sensory characteristics of wheat sourdough bread

The use of soya and flaxseed flours fermented with Pediococcus acidilactici for wheat sourdough bread production was investigated. The protein digestibility, biogenic amine contents of soya and flaxseed sourdoughs, texture and sensory features of bread were studied. The fermentation with P. acidilactici significantly improved soya and flaxseed protein extraction and increased protein digestibility on an average by 13.5%. The concentrations of histamine (3.8?±?2.3 and 4.0?±?0.2?mg/kg), tyramine (4.6?±?0.7 and 19.3?±?1.8?mg/kg) and putrescine (66.4?±?1.3 and 11.3?±?3.0?mg/kg) do not present a health risk for consumers due to their relatively low levels in fermented plant products. The flaxseed sourdoughs influenced a 17.5% higher specific volume and a 4.6% lower crumb hardness of bread than those of soya sourdoughs, and did not disimprove sensory properties of bread. However, the fermented soya additives decreased acceptability of bread because of intensive taste and odour.     

Emergency hospital admission for pain in palliative patients: A crucial role for general practitioners

Abstract

Introduction: In previous papers we analysed the incidence of wheezing in young children living near the iron and steel factory in C?l?ra?i, and in a control region (Rose?i) without industrial air pollution. Research question: Is industrial air pollution exposure during the first years of life a risk factor for the presence of asthmatic symptoms in children at school age? Methods: We assessed the prevalence of asthma symptoms using the ISAAC short form questionnaire for children aged 6–7 years, and measured the FEV1 and PEF in the children of both municipalities (297 children in C?l?ra?i, i.e. the exposed cohort, and 237 in Rose?i, i.e. the non-exposed cohort). Results: We found an OR of 7.2 (95% CI: 3.6–14.3) for affirmative answers to at least one of ISAAC questions for children living in C?l?ra?i compared to the children in Rose?i. The numbers of affirmative answers to all but one of the ISAAC questions were significantly higher in C?l?ra?i. The main result remained robust after adjusting for a series of co-variables using multiple logistic regression analysis (OR 14.8; 95% CI: 4.8–46.1). There was a strong relation between early life wheezing and asthma symptoms at school age (OR 9.0; 95%CI: 3.4–23.5).

Conclusion: Children, who had been living near an iron and steel factory during their early years, are still at increased risk for asthma symptoms at school age.     

The influence of a fruit smoothie or cereal and milk breakfast on subsequent dietary intake: a pilot study

Smoothies are popular breakfast foods. This study examined the effect of consuming Cereal & Milk (CM) or a nutritionally-comparable Fruit Smoothie (FS) for breakfast on daily energy intake (EI) in free-living adults and the extent to which individuals compensated for calories ingested in a High Energy Fruit Smoothie (HE). Ten participants (28.4?±?2.2y; 23.3?±?1.0?kg·m ^?2, Mean?±?SEM) attended the laboratory on 3 consecutive days per week for 3?weeks. Each week, they received a CM, FS or HE breakfast, then recorded all food/beverages consumed across the remainder of the day. The CM and FS were energy-matched to participants’ usual breakfast (1675?±?283?kJ), while the HE contained an additional 100?kJ·kg^?1 of maltodextrin (3019?±?335?kJ). Mean 3-day EI was similar on CM and FS (7894?±?547 vs. 7570?±?463?kJ, p?>?.05), but elevated on HE (8861?±?726?kJ, p?= .012). Thus, individuals who substitute CM for a FS breakfast should be mindful that energy-dense beverages may result in increased daily EI.     

Effect of hydrolysed egg protein on brain tryptophan availability

Serotonin synthesis critically depends on plasma levels of tryptophan (TRP). Earlier studies have shown that for mood and cognitive benefits to occur, the ratio between TRP and other large neutral amino acids (LNAA) has to be increased by approximately 40?%. The present study investigated the dose-dependent effects of a TRP-rich hydrolysed protein (egg-protein hydrolysate, EPH) on the plasma TRP:LNAA. Moreover, it was investigated whether EPH could increase TRP:LNAA in the presence of 2?g of milk protein (MP). In a randomised double-blind crossover design, plasma amino acids were measured every 30?min for 3·5?h after ingestion of a drink containing either three different doses of 4, 8 and 12?g EPH containing 270, 560 or 800?mg of TRP, respectively, the combination of 4?g EPH and 2?g MP (74?mg TRP), or 4?g MP (148?mg TRP) in twenty healthy subjects with a mean age of 52 years. All three EPH doses caused significant increases of TRP:LNAA above 40?% at 30, 60 and 90?min after consumption in a dose-dependent manner. Compared with the 4?g EPH, the increase in TRP:LNAA in the 4?g EPH with 2?g MP condition was significantly lower at 60?min (63 v. 44?%, P?0·05). The present study showed that a low dose of 4?g EPH with even the addition of 2?g MP was sufficient to increase the ratio of TRP:LNAA above 40?%. Thus, EPH offers a viable ingredient to increase TRP availability.     

The cooling profile of hot-cooked mussels stored in domestic insulated coolers amongst food vendors in Prince Edward Island,Canada

It is common during outdoor events on Prince Edward Island, Canada for vendors to store hot-cooked mussels in domestic coolers. Provincial legislation states that hot product should be maintained at a minimum of 60?°C. A study was conducted to ascertain how long mussels could be stored before the temperature decreased to less than 60?°C. Hot, cooked mussels were placed into coolers and the temperature measured every 10?min for 4?h. It was found that when the cooler was unopened, the mean temperature dropped to less than 60?°C in 56?min. For coolers opened every 10?min, the mean temperature decreased to less than 60?°C in 38?min. For coolers opened every 10?min with mussels removed, the mean temperature decreased to less than 60?°C in 52?min. It was concluded that mussels should not be stored for more than 30?min and temperature should be regularly monitored.     

Exploring Weathering: the Relation of Age to Low Birth Weight Among First Generation and Established United States-Born Mexican–American Women

To determine the age-related patterns of low birth weight, preterm birth, and intrauterine growth retardation among first generation and established US-born Mexican?CAmerican mothers. We performed stratified analyses on an Illinois transgenerational dataset of Mexican?CAmerican infants (1989?C1991) and their mothers (1956?C1976) with appended U.S. census income information. In Cook County, Illinois established (second or higher generation) US-born Mexican?CAmerican women (N?=?2,006) had a low birth weight (<2,500?g) rate of 6.2% compared to 4.8% for first generation US-born Mexican?CAmerican women (N?=?1,450), RR?=?1.3 (1.0?C1.6). In both subgroups, low birth weight, preterm, and intrauterine growth retarded components rates did not increase with advancing maternal age. First generation 30?C35?year old US-born Mexican?CAmerican women (N?=?159) had a low birth weight rate of 3.1% compared to 4.2% for their teen counterparts (N?=?386), RR?=?0.8 (0.3?C2.0). Established 30?C35?year old US-born Mexican?CAmerican women (N?=?330) had a low birth weight rate of 4.9% compared to 7.4% for their teen counterparts (N?=?459), RR?=?0.7 (0.4?C1.2). There was no evidence of weathering among US-born Mexican?CAmerican mothers with a lifelong residence in lower income neighborhoods, with a general downward trend in low birth weight rates with increasing age until age 30?C35. Rates of low birth weight, preterm birth, and intrauterine growth retardation do not increase with advancing age among first generation and established US-born 15?C35?year old Mexican?CAmerican women. This trend persists among both generations of women with a lifelong residence in lower income neighborhoods.     

EROD activity in peripheral blood lymphocytes and 1-hydroxypyrene in urine and milk as biomarkers of PAH exposure in dairy ruminants

Presently, few biomarker-based approaches are available for the evaluation of environmental exposure to persistent organic pollutants in dairy ruminants. In this study, goats (Capra hircus) were orally administered a mixture of pyrene, phenanthrene, and benzo[a]pyrene daily over a 40-d period (1 or 50?mg/d). Milk and urine 1-hydroxypyrene levels, ethoxyresorufin-O-deethylase (EROD) activity in peripheral blood lymphocytes (PBL) as well as urinary levels of 2- and 3-hydroxyphenanthrene were determined at 10-d intervals. 1-Hydroxypyrene excretion in milk and urine significantly increased and then achieved a plateau at 10?d. Transfer rates of 1-hydroxypyrene were calculated to be approximately 0.5 and 25% in milk and urine, respectively. Concentrations in milk and urine were proportional to the ingested doses. These results demonstrate that 1-hydroxypyrene in milk or urine may be used as a biomarker for evaluating the exposure of dairy ruminants to polycyclic aromatic hydrocarbons (PAHs) over an extended exposure period. Constitutive EROD activity in lymphocytes was 0.5?±?0.3?pmol resorufin/min/mg protein, and was significantly induced over the entire exposure time, before stabilizing after 40?d at 6.30?±?1.3 and 18.89?±?1.12?pmol resorufin/min/mg protein for 1?mg/d and 50?mg/d doses, respectively. Induction kinetics were calculated using a logistic-like model and approximate dose-response curves were designed. We therefore propose EROD activity in PBL as a relevant, convenient, and noninvasive biomarker of subchronic exposure of dairy ruminants to CYP450 inducing PAH.     

Social comparison and the young child: Current research issues

The paper represents a synthesis of the extensive literature on social comparison in young children. Several theorists are reviewed, whose writings provide a conceptual framework for the study of social comparison. Then, the paper overviews research pertaining to the following issues: What motivates children to engage in social comparison? With whom do children seek to compare? At what age does social comparison appear? Does it follow a developmental progression? What are the effects upon subsequent behavior? Are there sex‐related differences in social comparison activity? By way of conclusion, practical implications for teaching are drawn.     

Long-Term Effects of Antibiotics on the Elimination of Chemical Oxygen Demand, Nitrification, and Viable Bacteria in Laboratory-Scale Wastewater Treatment Plants

Antibiotics and other pharmaceuticals are contaminants of the environment because of their widespread use and incomplete removal by microorganisms during wastewater treatment. The influence of a mixture of ciprofloxacin (CIP), gentamicin (GM), sulfamethoxazole (SMZ)/trimethoprim (TMP), and vancomycin (VA), up to a final concentration of 40?mg/L, on the elimination of chemical oxygen demand (COD), nitrification, and survival of bacteria, as well as the elimination of the antibiotics, was assessed in a long-term study in laboratory treatment plants (LTPs). In the presence of 30?mg/L antibiotics, nitrification of artificial sewage by activated sludge ended at nitrite. Nitrate formation was almost completely inhibited. No nitrification at all was possible in the presence of 40?mg/L antibiotics. The nitrifiers were more sensitive to antibiotics than heterotrophic bacteria. COD elimination in antibiotic-stressed LTPs was not influenced by?≤20?mg/L antibiotics. Addition of 30?mg/L antibiotic mixture decreased COD removal efficiency for a period, but the LTPs recovered. Similar results were obtained with 40?mg/L antibiotic mixture. The total viable count of bacteria was not affected negatively by the antibiotics. It ranged from 2.2?×?10(6) to 8.2?×?10(6) colony-forming units per milliliter (CFU/mL) compared with the control at 1.4?×?10(6)-6.3?×?10(6) CFU/mL. Elimination of the four antibiotics during phases of 2.4-30?mg/L from the liquid was high for GM (70-90?%), much lower for VA, TMP, and CIP (0-50?%), and highly fluctuating for SMZ (0-95?%). The antibiotics were mainly adsorbed to the sludge and not biodegraded.