lower processing temperature
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Současné poznatky moderně chápané nutriční imunologie mají zásadní význam z hlediska aktivit v oblasti ochrany a podpory zdraví. Existuje nespočet dokladů, že neadekvátní nebo snížený nutriční příjem se neodráží jen klasickými příznaky proteinové a energetické malnutrice, ale také nepříznivým ovlivněním až selháváním imunitních funkcí. Stále rostoucí počet in vitro a in vivo experimentálních a klinických studií dokládá, že produkty neenzymatických reakcí, které vznikají při technologickém a kulinárním zpracování potravin mohou hrát významnou roli při vzniku a globálním šíření chronických nesdělných onemocnění. Prokazuje se, že hlavní patogenetický význam mají tzv. konečné produkty pokročilé glykace (AGE, Advanced Glycation End products), lipoxidace (ALE, Advanced Lipoxidation End products), a oxidace proteinů (AOPP, Advanced Oxidation Protein Products), které představují nejdůležitější nutriční složky kumulující se ve vnitřním prostředí organismu v průběhu jeho celého života. V současnosti jsou považovány za nejčastější složky poškozující zdraví a zároveň představující jednu z významných příčinu růstu incidence chronických nesdělných nemocí ve všech zemích, které přijaly "západní" životní styl.
The recent results of research in the field of nutritional immunology have a wide impact on health protection and promotion-related activities. There is a great deal of evidence showing that the inadequate or lowered nutritional intake is reflected in both protein-energetic malnutrition and immune system disorders. A growing number of in vitro/in vivo experimental and clinical studies documents that the products of non-enzymatic reactions formed during technological and culinary processing of food may play a major role in the emergence and global spread of chronic non-communicable diseases. Evidence mainly points to the pathogenic role of advanced glycation end products (AGE), advanced lipoxidation end products (ALE), and advanced oxidation protein products (AOPP), which represent the most important dietary compounds that accumulate within the internal milieu of an organism over a whole life span. Currently, these factors are regarded as one of a row of causations with strong negative influence on health and the most frequent causative agents of increasing chronic disease burden in all countries which adopt a "westernized lifestyle".
- Klíčová slova
- technologizovaná strava, Advanced Lipoxidation End products, produkty pokročilé lipoxidace,
- MeSH
- antioxidancia MeSH
- chronická nemoc * MeSH
- fyziologie výživy MeSH
- konzervace potravin MeSH
- kvalita jídla * MeSH
- lidé MeSH
- manipulace s potravinami MeSH
- potravinářská technologie MeSH
- produkty pokročilé glykace * škodlivé účinky MeSH
- produkty pokročilé oxidace proteinů škodlivé účinky MeSH
- průmysl zpracování potravin MeSH
- stravovací zvyklosti MeSH
- teplota MeSH
- západní dieta škodlivé účinky MeSH
- životní styl MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
Phlebotomus papatasi (Scopoli) (Diptera: Psychodidae) is the most important vector of Leishmania major, and previous experiments revealed that Leishmania development in the sand fly midgut is significantly affected by temperature. Therefore, we maintained blood-fed P. papatasi females at 23 or 28 degrees C to understand the effect of temperature on bloodmeal digestion and developmental times of this sand fly. At the lower temperature, the metabolic processes were slower and developmental times were longer: defecation, oviposition, and egg hatch started later and took longer to complete. Also, the mortality of blood-fed females was significantly lower. The defecation of bloodmeal remains was delayed for 12-36 h at 23 degrees C compared with the group maintained at 28 degrees C. Such delay would provide more time for Leishmania to establish the midgut infection and could partially explain the increased susceptibility of P. papatasi to Leishmania major at 23 degrees C. In both experimental groups, blood-fed females laid similar numbers of eggs (mean 60 and 70, maximum 104 and 115 per female). Egg numbers were positively correlated with the amount of hematin excreted in feces of ovipositing females. In parallel experiments, autogeny was recorded in 8% of females. The autogenous egg batches were smaller (mean, 12; range, 1-39), but they all produced viable larvae.
- MeSH
- analýza přežití MeSH
- časové faktory MeSH
- financování organizované MeSH
- hemin analýza sekrece MeSH
- hmyz - vektory metabolismus růst a vývoj MeSH
- kladení vajíček fyziologie MeSH
- ovum růst a vývoj MeSH
- Phlebotomus metabolismus růst a vývoj MeSH
- statistika jako téma MeSH
- teplota MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
BACKGROUND AND AIMS: The egg protein ovalbumin (OVA) belongs to six most frequent food allergens. We investigated how thermal processing influences its ability to induce allergic symptoms and immune responses in mouse model of food allergy. METHODOLOGY/PRINCIPAL FINDINGS: Effect of increased temperature (70°C and 95°C) on OVA secondary structure was characterized by circular dichroism and by the kinetics of pepsin digestion with subsequent HPLC. BALB/c mice were sensitized intraperitoneally and challenged with repeated gavages of OVA or OVA heated to 70°C (h-OVA). Levels of allergen-specific serum antibodies were determined by ELISA (IgA and IgGs) or by β-hexosaminidase release test (IgE). Specific activities of digestive enzymes were determined in brush border membrane vesicles of jejunal enterocytes. Cytokine production and changes in regulatory T cells in mesenteric lymph nodes and spleen were assessed by ELISA and FACS. Heating of OVA to 70°C caused mild irreversible changes in secondary structure compared to boiling to 95°C (b-OVA), but both OVA treatments led to markedly different digestion kinetics and Tregs induction ability in vitro, compared to native OVA. Heating of OVA significantly decreased clinical symptoms (allergic diarrhea) and immune allergic response on the level of IgE, IL-4, IL-5, IL-13. Furthermore, h-OVA induced lower activities of serum mast cell protease-1 and enterocyte brush border membrane alkaline phosphatase as compared to native OVA. On the other hand h-OVA stimulated higher IgG2a in sera and IFN-γ secretion by splenocytes. CONCLUSIONS: Minor irreversible changes in OVA secondary structure caused by thermal processing changes both its digestion and antigenic epitopes formation, which leads to activation of different T cell subpopulations, induces shift towards Th1 response and ultimately reduces its allergenicity.
- MeSH
- cytokiny krev imunologie MeSH
- imunoglobulin E krev imunologie MeSH
- modely nemocí na zvířatech MeSH
- myši MeSH
- ovalbumin chemie imunologie MeSH
- potravinová alergie krev imunologie MeSH
- prezentace antigenu imunologie MeSH
- regulační T-lymfocyty imunologie MeSH
- sekundární struktura proteinů MeSH
- vysoká teplota MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
In some applications of thermography, spatial orientation of the thermal infrared information can be desirable. By the photogrammetric processing of thermal infrared (TIR) images, it is possible to create 2D and 3D results augmented by thermal infrared information. On the augmented 2D and 3D results, it is possible to locate thermal occurrences in the coordinate system and to determine their scale, length, area or volume. However, photogrammetric processing of TIR images is difficult due to negative factors which are caused by the natural character of TIR images. Among the negative factors are the lower resolution of TIR images compared to RGB images and lack of visible features on the TIR images. To eliminate these negative factors, two methods of photogrammetric co-processing of TIR and RGB images were designed. Both methods require a fixed system of TIR and RGB cameras and for each TIR image a corresponding RGB image must be captured. One of the methods was termed sharpening and the result of this method is mainly an augmented orthophoto, and an augmented texture of the 3D model. The second method was termed reprojection and the result of this method is a point cloud augmented by thermal infrared information. The details of the designed methods, as well as the experiments related to the methods, are presented in this article.
- MeSH
- fotogrammetrie * MeSH
- termografie * metody MeSH
- Publikační typ
- časopisecké články MeSH
Crocosphaera is a major dinitrogen (N2)-fixing microorganism, providing bioavailable nitrogen (N) to marine ecosystems. The N2-fixing enzyme nitrogenase is deactivated by oxygen (O2), which is abundant in marine environments. Using a cellular scale model of Crocosphaera sp. and laboratory data, we quantify the role of three O2 management strategies by Crocosphaera sp.: size adjustment, reduced O2 diffusivity, and respiratory protection. Our model predicts that Crocosphaera cells increase their size under high O2 Using transmission electron microscopy, we show that starch granules and thylakoid membranes are located near the cytoplasmic membranes, forming a barrier for O2 The model indicates a critical role for respiration in protecting the rate of N2 fixation. Moreover, the rise in respiration rates and the decline in ambient O2 with temperature strengthen this mechanism in warmer water, providing a physiological rationale for the observed niche of Crocosphaera at temperatures exceeding 20°C. Our new measurements of the sensitivity to light intensity show that the rate of N2 fixation reaches saturation at a lower light intensity (∼100 μmol m-2 s-1) than photosynthesis and that both are similarly inhibited by light intensities of >500 μmol m-2 s-1 This suggests an explanation for the maximum population of Crocosphaera occurring slightly below the ocean surface.IMPORTANCECrocosphaera is one of the major N2-fixing microorganisms in the open ocean. On a global scale, the process of N2 fixation is important in balancing the N budget, but the factors governing the rate of N2 fixation remain poorly resolved. Here, we combine a mechanistic model and both previous and present laboratory studies of Crocosphaera to quantify how chemical factors such as C, N, Fe, and O2 and physical factors such as temperature and light affect N2 fixation. Our study shows that Crocosphaera combines multiple mechanisms to reduce intracellular O2 to protect the O2-sensitive N2-fixing enzyme. Our model, however, indicates that these protections are insufficient at low temperature due to reduced respiration and the rate of N2 fixation becomes severely limited. This provides a physiological explanation for why the geographic distribution of Crocosphaera is confined to the warm low-latitude ocean.
- MeSH
- fixace dusíku * MeSH
- kyslík metabolismus MeSH
- sinice cytologie metabolismus účinky záření MeSH
- škrob metabolismus MeSH
- světlo * MeSH
- teplota * MeSH
- transmisní elektronová mikroskopie MeSH
- tylakoidy metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
The present study investigated the effects of head cooling during endurance cycling on performance and the serotonergic neuroendocrine response to exercise in the heat. Subjects exercised at 75 % VO2max to volitional fatigue on a cycle ergometer at an ambient temperature of 29±1.0 °C, with a relative humidity of approximately 50 %. Head cooling resulted in a 51 % (p<0.01) improvement in exercise time to fatigue and Borg Scale ratings of perceived exertion were significantly lower throughout the exercise period with cooling (p<0.01). There were no indications of peripheral mechanisms of fatigue either with, or without, head cooling, indicating the importance of central mechanisms. Exercise in the heat caused the release of prolactin in response to the rise in rectal temperature. Head cooling largely abolished the prolactin response while having no effect on rectal temperature. Tympanic temperature and sinus skin temperature were reduced by head cooling and remained low throughout the exercise. It is suggested that there is a coordinated response to exercise involving thermoregulation, neuroendocrine secretion and behavioural adaptations that may originate in the hypothalamus or associated areas of the brain. Our results are consistent with the effects of head cooling being mediated by both direct cooling of the brain and modified cerebral artery blood flow, but an action of peripheral thermoreceptors cannot be excluded.
- Klíčová slova
- Prolactin, Hyperthermia, Head Cooling, Exercise, Central Fatigue,
- MeSH
- časové faktory MeSH
- dospělí MeSH
- financování organizované MeSH
- fyzická vytrvalost MeSH
- fyziologická adaptace MeSH
- hlava MeSH
- kosterní svaly metabolismus MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- nízká teplota MeSH
- percepce MeSH
- prolaktin krev MeSH
- spotřeba kyslíku MeSH
- svalová kontrakce MeSH
- svalová únava MeSH
- teplota kůže MeSH
- termoregulace MeSH
- vysoká teplota MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
Knowledge of the active pharmaceutical ingredient (API) solubility in a polymer is imperative for successful amorphous solid dispersion design and formulation but acquiring this information at storage temperature is challenging. Various solubility determination methods have been established, which utilize differential scanning calorimetry (DSC). In this work, three commonly used DSC-based protocols [i.e., melting point depression (MPD), recrystallization, and zero-enthalpy extrapolation (Z-EE)] and a method that we have developed called "step-wise dissolution" (S-WD) were analyzed. For temperature-composition phase diagram construction, two glass-transition temperature equations (i.e., those of Gordon-Taylor and Kwei) and three solid-liquid equilibrium curve modeling approaches [i.e., the Flory-Huggins model, an empirical equation, and the perturbed-chain statistical associating fluid theory (PC-SAFT) equation of state (EOS)] were considered. Indomethacin (IND) and Kollidon 12 PF (PVP K12) were selected as the API and polymer, respectively. An annealing time investigation revealed that the IND-PVP K12 dissolution process was remarkably faster than demixing, which contradicted previously published statements. Thus, the recrystallization method overestimated the solubility of IND in PVP K12 when a 2-h time of annealing was set as the benchmark. Likewise, the MPD and Z-EE methods overestimated the API solubility because of unreliable IND melting endotherm evaluation at lower API loadings and a relatively slow heating rate, respectively. When the experimental results obtained using the S-WD method (in conjunction with the Kwei equation) were applied to the PC-SAFT EOS, which was regarded as the most reliable combination, the predicted IND solubility in PVP K12 at T = 25 °C was approximately 40 wt %. When applicable, the S-WD method offers the advantage of using a limited number of DSC sample pans and API-polymer physical mixture compositions, which is both cost- and time-effective.
The freezing process consists of dissipating heat from the product until the final temperature is lower than the temperature of crystallisation of that product. Freezing can be used for numerous applications, including for disruption of waste-activated sludge (WAS). The aim of this study was to calculate the estimated amount of heat conveyed between the solidified carbon dioxide and the WAS, in the following ratios: 0.25:1; 0.5:1; 0.75:1 and 1:1. In heat of phase transformations, dry ice sublimation, water solidification, the amount of heat transferred by other substances and heat transferred from the sludge (dry sludge) were taken into account during the process of WAS freezing. Heat changes on the surface of WAS were registered using a thermovision camera. The effectiveness of WAS disintegration was confirmed by several biochemical parameters such as soluble chemical oxygen demand (increase over 14 times), degree of disintegration (48%), proteins (increase over 5 times), carbohydrates (increase almost 7 times), RNA (increase by 2.23 mg L-1), ammonia nitrogen (increase over 23 times), phosphates (increase almost 27 times) and turbidity (increased over 7 times). It was found that dry ice pretreatment of WAS can be an intriguing alternative for the conventional methods used.
The aim of this study was to ascertain whether repeated local cooling induces the same or different adaptational responses as repeated whole body cooling. Repeated cooling of the legs (immersion into 12 °C water up to the knees for 30 min, 20 times during 4 weeks = local cold adaptation – LCA) attenuated the initial increase in heart rate and blood pressure currently observed in control subjects immersed in cold water up to the knees. After LCA the initial skin temperature decrease tended to be lower, indicating reduced vasoconstriction. Heart rate and systolic blood pressure appeared to be generally lower during rest and during the time course of cooling in LCA humans, when compared to controls. All these changes seem to indicate attenuation of the sympathetic tone. In contrast, the sustained skin temperature in different areas of the body (finger, palm, forearm, thigh, chest) appeared to be generally lower in LCA subjects than in controls (except for temperatures on the forehead). Plasma levels of catecholamines (measured 20 and 40 min after the onset of cooling) were also not influenced by local cold adaptation. Locally cold adapted subjects, when exposed to whole body cold water immersion test, showed no change in the threshold temperature for induction of cold thermogenesis. This indicates that the hypothermic type of cold adaptation, typically occurring after systemic cold adaptation, does not appear after local cold adaptation of the intensity used. It is concluded that in humans the cold adaptation due to repeated local cooling of legs induces different physiological changes than systemic cold adaptation.
- MeSH
- financování vládou MeSH
- fyziologická adaptace fyziologie genetika MeSH
- kardiovaskulární fyziologické jevy MeSH
- katecholaminy fyziologie krev MeSH
- lidé MeSH
- metabolismus fyziologie MeSH
- nízká teplota škodlivé účinky MeSH
- terapeutická hypotermie klasifikace MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- srovnávací studie MeSH
