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1.
Milk subjected to instant infusion pasteurization (IIP) at 72 °C, 100 °C and 120 °C (holding time 0.2 s) exhibited increased rennet coagulation time and decreased curd firming rate for increasing heat treatment temperature, when compared with raw or high temperature short time pasteurized (HTST) milk. However, addition of 4.5 mm or 9.0 mm of calcium restored the impaired rennet coagulation ability. Open texture cheeses produced from IIP milk (100 °C and 120 °C) contained significantly more moisture, had lower pH and shorter texture than similar cheese from IIP at 72 °C and HTST pasteurized milk. Cheese ripening was also affected by heat treatment, and different patterns of casein breakdown and peptide formation resulted from cheeses made from milk treated to IIP at 100 °C and 120 °C compared with cheeses made using IIP at 72 °C or HTST.  相似文献   
2.

Background

Engineered nanoparticles are smaller than 100 nm and designed to improve or creating even new physico-chemical properties. Consequently, toxicological properties of materials may change as size reaches the nm size-range. We examined outcomes related to the central nervous system in the offspring following maternal inhalation exposure to nanosized carbon black particles (Printex 90).

Methods

Time-mated mice (NMRI) were exposed by inhalation, for 45 min/day to 0, 4.6 or 37 mg/m3 aerosolized carbon black on gestation days 4–18, i.e. for a total of 15 days. Outcomes included maternal lung inflammation (differential cell count in bronchoalveolar lavage fluid and Saa3 mRNA expression in lung tissue), offspring neurohistopathology and behaviour in the open field test.

Results

Carbon black exposure did not cause lung inflammation in the exposed females, measured 11 or 28–29 days post-exposure. Glial fibrillary acidic protein (GFAP) expression levels were dose-dependently increased in astrocytes around blood vessels in the cerebral cortex and hippocampus in six weeks old offspring, indicative of reactive astrogliosis. Also enlarged lysosomal granules were observed in brain perivascular macrophages (PVMs) in the prenatally exposed offspring. The number of parvalbumin-positive interneurons and the expression levels of parvalbumin were decreased in the motor and prefrontal cortices at weaning and 120 days of age in the prenatally exposed offspring. In the open field test, behaviour was dose-dependently altered following maternal exposure to Printex 90, at 90 days of age. Prenatally exposed female offspring moved a longer total distance, and especially males spent significantly longer time in the central zone of the maze. In the offspring, the described effects were long-lasting as they were present at all time points investigated.

Conclusion

The present study reports for the first time that maternal inhalation exposure to Printex 90 carbon black induced dose-dependent denaturation of PVM and reactive astrocytes, similarly to the findings observed following maternal exposure to Printex 90 by airway instillation. Of note, some of the observed effects have striking similarities with those observed in mouse models of neurodevelopmental disorders.
  相似文献   
3.
Hydrophilic insulins, more positively charged than human insulinat neutral pH, have been prepared by substitution with basicamino acids at the termini of the B-chain and by blocking theC-terminal carboxyl group of the B-chain. The iso-electric pHof the insulin is thereby moved from 5.4 towards physiologicallevels. Slightly acid solutions of derivatives, in which chargehas been added in the C-terminus of the B-chain, have a prolongedaction in vivo, in particular if the carboxyl group is blocked.It is found that the prolong ed-acting hydrophilic insulinscrystallize instantly when the pH is adjusted to 7. The prolongedaction is ascribed to this readiness to crystallization combinedwith a low solubility, which may be further decreased by Increasedconcentration of zinc ions. Hydrophobic insulins have a prolongedaction independent of the site of substitution even if the derivativeis soluble at physiological pH. Some derivatives were preparedfrom porcine Insulin by tryptic transpeptidatlon. N-terminalB-chain substituted insulins were prepared by alkylation ofa biosynthetic single-chain insulin precursor, followed by tryptictranspeptidation rendering the double chain insulin derivative.The observed blood glucose lowering in the rabbits implies thatneither N- nor C-terminal B-chain substitution results in substantialdeterioration of biological potency. An index for the degreeof protraction based on the blood glucose data is used to comparethe insulins.  相似文献   
4.
The impact of microalbuminuria and macroalbuminuria on mortality was evaluated prospectively in 328 Caucasian patients with non-insulin-dependent diabetes mellitus (NIDDM) followed for five years. One hundred and ninety-one patients with normoalbuminuria (albumin excretion rate (AER) < 30 mg/24 h), 86 patients with microalbuminuria (AER 30-299 mg/24 h), and 51 patients with macroalbuminuria (AER > or = 300 mg/24 h) all less than 66 years old at start of the study were followed from 1987 until death or until 1 January 1993. Eight percent of patients with normoalbuminuria, 20% of patients with microalbuminuria, and 35% of patients with macroalbuminuria had died, predominantly from cardiovascular disease. Significant predictors of all-cause mortality included preexisting coronary heart disease, AER, HbA1c level and age. Significant predictors of cardiovascular mortality included preexisting coronary heart disease, macroalbuminuria, HbA1c level and systolic blood pressure. Abnormally elevated urinary albumin excretion and poor glycaemic control indicate a substantially increased all-cause, mainly cardiovascular, mortality risk in NIDDM patients.  相似文献   
5.
Insulin regimens and metabolic control in children and adolescents with Type 1 diabetes mellitus were evaluated in a cross-sectional, non-population-based investigation, involving 22 paediatric departments, from 18 countries in Europe, Japan, and North America. Blood samples and information were collected from 2873 children from March to August 1995. HbA1c was determined once and analysed centrally (normal range 4.4-6.3%, mean 5.4%). Year of birth, sex, duration of diabetes, height, body weight, number of daily insulin injections, types and doses of insulin were recorded. Average HbA1c in children under 11 years was 8.3 +/- 1.3% (mean +/- SD) compared with 8.9 +/- 1.8% in those aged 12-18 years. The average insulin dose per kg body weight was almost constant (0.65 U kg(-1) 24 h(-1)) in children aged 2-9 years for both sexes, but there was a sharp increase during the pubertal years, particularly in girls. The increase in BMI of children with diabetes was much faster during adolescence compared to healthy children, especially in females. Sixty per cent of the children (n = 1707) used two daily insulin injections while 37% (n = 1071) used three or more. Of those on two or three injections daily, 37% used pre-mixed insulins, either alone or in combination with short- and intermediate-acting insulin. Pre-adolescent children on pre-mixed insulin showed similar HbA1c levels to those on a combination of short- and long-acting insulins, whereas in adolescents significantly better HbA1c values were achieved with individual combinations. Very young children were treated with a higher proportion of long-acting insulin. Among adolescent boys, lower HbA1c was related to use of more short-acting insulin. This association was not found in girls. We conclude that numerous insulin injection regimens are currently used in paediatric diabetes centres around the world, with an increasing tendency towards intensive diabetes management, particularly in older adolescents. Nevertheless, the goal of near normoglycaemia is achieved in only a few.  相似文献   
6.

Background

Results from epidemiological studies indicate that particulate air pollution constitutes a hazard for human health. Recent studies suggest that diesel exhaust possesses endocrine activity and therefore may affect reproductive outcome. This study in mice aimed to investigate whether exposure to diesel exhaust particles (DEP; NIST 2975) would affect gestation, postnatal development, activity, learning and memory, and biomarkers of transplacental toxicity. Pregnant mice (C57BL/6; BomTac) were exposed to 19 mg/m3 DEP (~1·106 particles/cm3; mass median diameter ? 240 nm) on gestational days 9–19, for 1 h/day.

Results

Gestational parameters were similar in control and diesel groups. Shortly after birth, body weights of DEP offspring were slightly lower than in controls. This difference increased during lactation, so by weaning the DEP exposed offspring weighed significantly less than the control progeny. Only slight effects of exposure were observed on cognitive function in female DEP offspring and on biomarkers of exposure to particles or genotoxic substances.

Conclusion

In utero exposure to DEP decreased weight gain during lactation. Cognitive function and levels of biomarkers of exposure to particles or to genotoxic substances were generally similar in exposed and control offspring. The particle size and chemical composition of the DEP and differences in exposure methods (fresh, whole exhaust versus aged, resuspended DEP) may play a significant role on the biological effects observed in this compared to other studies.  相似文献   
7.
Casein‐based powders are gaining industrial interest due to their nutritional and functional properties, but they are also known to have poor rehydration abilities. The fundamental physical and chemical mechanisms involved in the rehydration of these powders are essential for determining the critical steps in the manufacturing processes and for developing casein powders with improved rehydration properties. A number of analytical methods have been developed to measure the rehydration ability of powders, but criteria for the selection of methods for casein‐based powders have not been provided. This review article provides an overview of the characteristics and methods for the production of casein‐based powders, methodologies to measure their rehydration properties, and it summarizes the current state of understanding regarding rehydration. Advancements have been made in the field; however, a fundamental understanding enabling improvement of the rehydration properties of these powders is still lacking.  相似文献   
8.
A class of continuous multivariate distributions is reviewed. It is derived in a survival/reliability context, where the dependence is modeled as random effects, viz, by an unobserved covariate common to the components in a system and assumed to follow a positive stable distribution. Accounting for censored data is straightforward. The class is well fitted to proportional hazard models, and distributions of minima are simple. An important subfamily is the multivariate Weibull distributions. The theory is illustrated with an example  相似文献   
9.
Bayesian model comparison in nonlinear BOLD fMRI hemodynamics   总被引:1,自引:0,他引:1  
Nonlinear hemodynamic models express the BOLD (blood oxygenation level dependent) signal as a nonlinear, parametric functional of the temporal sequence of local neural activity. Several models have been proposed for both the neural activity and the hemodynamics. We compare two such combined models: the original balloon model with a square-pulse neural model (Friston, Mechelli, Turner, & Price, 2000) and an extended balloon model with a more sophisticated neural model (Buxton, Uludag, Dubowitz, & Liu, 2004). We learn the parameters of both models using a Bayesian approach, where the distribution of the parameters conditioned on the data is estimated using Markov chain Monte Carlo techniques. Using a split-half resampling procedure (Strother, Anderson, & Hansen, 2002), we compare the generalization abilities of the models as well as their reproducibility, for both synthetic and real data, recorded from two different visual stimulation paradigms. The results show that the simple model is the better one for these data.  相似文献   
10.
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