198 research outputs found
Cross Section Measurement of Long Cylindrical Products without Contact using Long Cylindrical Coils
The impedance Z of a solenoid with a conducting piece near it when capacity effects are neglected is Z = R + jωL with (1) R=Re−NωφosinϕIo (2) L=NωφocosϕIo where Re is the resistance of the wire of the coil, N is the number of single turns of the coil, Φo is the amplitude of the mean magnetic flux crossing the coil, Io is the amplitude of the current I circulating in the coil, ω is the pulsation of the current and ϕ is the phase of the flux relative to the current
Death kinetics of Escherichia coli in goat milk and Bacillus licheniformis in cloudberry jam treated by ohmic heating
In recent years, the world’s food industry has focused increasing attention on electrical techniques of
food processing. Ohmic heating is one of these techniques that can be considered as a high temperature
short time and a purely bulk heating method, having potential applications in processes such as
blanching, evaporation and pasteurization in the food industry. However such technology would have
to assure the microbiological safety obtained by the conventional cooking methods. Concerning this,
the influence of heat treatment by ohmic and conventional technology on death kinetic parameters (D
and z values) of Escherichia coli ATCC® 25922 was studied in goat milk. In ohmic treatment lower D
values were obtained (D60ºC = 4.2 min, D63ºC = 1.9 min, D65ºC = 0.86 min) as compared to conventional
treatment (D63ºC = 3.9 min, D65ºC = 3.5, D67ºC = 2.8 min, D75ºC = 1.5 min). The increase of temperature
required for a ten fold decrease in D value was also lower in the ohmic inactivation (z = 8.4 ºC)
comparing with the conventional inactivation (z = 23.1 ºC). The death kinetics for Bacillus
licheniformis ATCC® 14580 spores in cloudberry jam were also studied under both types of heat
inactivation (ohmic and conventional) and similar conclusions were drawn for the D values; lower D
values were also obtained for ohmic treatment (D70ºC = 57.1 min, D75ºC = 25.2 min, D80ºC = 7.2 min) as
compared to conventional treatment (D70ºC = 85.3 min, D75ºC = 51.0, D80ºC = 18.1 min, D85ºC = 6.0 min,
D90ºC = 1.6 min). However, between the z values obtained for those treatments (z ohmic = 11.1 ºC and z
conventional = 11.4 ºC) the differences were not significant. In general the results of present work indicate
that the ohmic heating provides quicker death kinetics. This opens the perspective for shorter, less
aggressive treatments
Air–liquid interface cultures enhance the oxygen supply and trigger the structural and functional differentiation of intestinal porcine epithelial cells (IPEC)
The specific function of the epithelium as critical barrier between the intestinal lumen and the organism’s internal microenvironment is reflected by permanent maintenance of intercellular junctions and cellular polarity. The intestinal epithelial cells are responsible for absorption of nutritional components, facing mechanical stress and a changing oxygen supplementation via blood stream. Oxygen itself can regulate the barrier and the absorptive function of the epithelium. Therefore, we compared the dish cell culture, the transwell-like membrane culture and the oxygen enriched air–liquid interface (ALI) culture. We demonstrated strong influence of the different culture conditions on morphology and function of intestinal porcine epithelial cell lines in vitro. ALI culture resulted in a significant increase in cell number, epithelial cell layer thickness and expression as well as apical localisation of the microvilli-associated protein villin. Remarkable similarities regarding the morphological parameters were observed between ALI cultures and intestinal epithelial cells in vivo. Furthermore, the functional analysis of protein uptake and degradation by the epithelial cells demonstrated the necessity of sufficient oxygen supply as achieved in ALI cultures. Our study is the first report providing marked evidence that optimised oxygen supply using ALI cultures directly affects the morphological differentiation and functional properties of intestinal epithelial cells in vitro
Genetic architecture of the APM1 gene and its influence on adiponectin plasma levels and parameters of the metabolic syndrome in 1,727 healthy Caucasians
Copyright: Copyright 2008 Elsevier B.V., All rights reserved.The associations of the adiponectin (APM1) gene with parameters of the metabolic syndrome are inconsistent. We performed a systematic investigation based on fine-mapped single nucleotide polymorphisms (SNPs) highlighting the genetic architecture and their role in modulating adiponectin plasma concentrations in a particularly healthy population of 1,727 Caucasians avoiding secondary effects from disease processes. Genotyping 53 SNPs (average spacing of 0.7 kb) in the APM1 gene region in 81 Caucasians revealed a two-block linkage disequilibrium (LD) structure and enabled comprehensive tag SNP selection. We found particularly strong associations with adiponectin concentrations for 11 of the 15 tag SNPs in the 1,727 subjects (five P values <0.0001). Haplotype analysis provided a thorough differentiation of adiponectin concentrations with 9 of 17 haplotypes showing significant associations (three P values <0.0001). No significant association was found for any SNP with the parameters of the metabolic syndrome. We observed a two-block LD structure of APM1 pointing toward at least two independent association signals, one including the promoter SNPs and a second spanning the relevant exons. Our data on a large number of healthy subjects suggest a clear modulation of adiponectin concentrations by variants of APM1, which are not merely a concomitant effect in the course of type 2 diabetes or coronary artery disease.publishersversionPeer reviewe
Human Mesenchymal Stem Cells Self-Renew and Differentiate According to a Deterministic Hierarchy
BACKGROUND:Mesenchymal progenitor cells (MPCs) have been isolated from a variety of connective tissues, and are commonly called "mesenchymal stem cells" (MSCs). A stem cell is defined as having robust clonal self-renewal and multilineage differentiation potential. Accordingly, the term "MSC" has been criticised, as there is little data demonstrating self-renewal of definitive single-cell-derived (SCD) clonal populations from a mesenchymal cell source. METHODOLOGY/PRINCIPAL FINDINGS:Here we show that a tractable MPC population, human umbilical cord perivascular cells (HUCPVCs), was capable of multilineage differentiation in vitro and, more importantly, contributed to rapid connective tissue healing in vivo by producing bone, cartilage and fibrous stroma. Furthermore, HUCPVCs exhibit a high clonogenic frequency, allowing us to isolate definitive SCD parent and daughter clones from mixed gender suspensions as determined by Y-chromosome fluorescent in situ hybridization. CONCLUSIONS/SIGNIFICANCE:Analysis of the multilineage differentiation capacity of SCD parent clones and daughter clones enabled us to formulate a new hierarchical schema for MSC self-renewal and differentiation in which a self-renewing multipotent MSC gives rise to more restricted self-renewing progenitors that gradually lose differentiation potential until a state of complete restriction to the fibroblast is reached
Differences in the pattern and regulation of mineral deposition in human cell lines of osteogenic and non-osteogenic origin
Bone marrow-derived mesenchymal stem cells (MSCs) are widely used as a cellular model of bone formation, and can mineralize in vitro in response to osteogenic medium (OM). It is unclear, however, whether this property is specific to cells of mesenchymal origin. We analysed the OM response in 3 non-osteogenic lines, HEK293, HeLa and NTera, compared to MSCs. Whereas HEK293 cells failed to respond to OM conditions, the 2 carcinoma-derived lines NTera and HeLa deposited a calcium phosphate mineral comparable to that present in MSC cultures. However, unlike MSCs, HeLa and NTera cultures did so in the absence of dexamethasone. This discrepancy was confirmed, as bone morphogenetic protein inhibition obliterated the OM response in MSCs but not in HeLa or NTera, indicating that these 2 models can deposit mineral through a mechanism independent of established dexamethasone or bone morphogenetic protein signalling
Adipose Tissue Deficiency and Chronic Inflammation in Diabetic Goto-Kakizaki Rats
Type 2 diabetes (T2DM) is a heterogeneous group of diseases that is progressive and involves multiple tissues. Goto-Kakizaki (GK) rats are a polygenic model with elevated blood glucose, peripheral insulin resistance, a non-obese phenotype, and exhibit many degenerative changes observed in human T2DM. As part of a systems analysis of disease progression in this animal model, this study characterized the contribution of adipose tissue to pathophysiology of the disease. We sacrificed subgroups of GK rats and appropriate controls at 4, 8, 12, 16 and 20 weeks of age and carried out a gene array analysis of white adipose tissue. We expanded our physiological analysis of the animals that accompanied our initial gene array study on the livers from these animals. The expanded analysis included adipose tissue weights, HbA1c, additional hormonal profiles, lipid profiles, differential blood cell counts, and food consumption. HbA1c progressively increased in the GK animals. Altered corticosterone, leptin, and adiponectin profiles were also documented in GK animals. Gene array analysis identified 412 genes that were differentially expressed in adipose tissue of GKs relative to controls. The GK animals exhibited an age-specific failure to accumulate body fat despite their relatively higher calorie consumption which was well supported by the altered expression of genes involved in adipogenesis and lipogenesis in the white adipose tissue of these animals, including Fasn, Acly, Kklf9, and Stat3. Systemic inflammation was reflected by chronically elevated white blood cell counts. Furthermore, chronic inflammation in adipose tissue was evident from the differential expression of genes involved in inflammatory responses and activation of natural immunity, including two interferon regulated genes, Ifit and Iipg, as well as MHC class II genes. This study demonstrates an age specific failure to accumulate adipose tissue in the GK rat and the presence of chronic inflammation in adipose tissue from these animals
Foetal haemoglobin, blood transfusion, and retinopathy of prematurity in very preterm infants:A pilot prospective cohort study
Purpose
To identify if there is an association between foetal haemoglobin (HbF) concentration and retinopathy of prematurity (ROP) in very preterm infants.
Patients and methods
Prospective cohort study. Infants born <32 weeks’ gestational age or <1501 g in two tertiary neonatal units between January 2012 and May 2013 (n=42) were enrolled. HbF and adult haemoglobin (HbA) concentrations were measured using high-pressure liquid chromatography from blood samples sent as part of routine neonatal care once routinely requested laboratory tests had been performed. Clinical data were obtained from case notes. We calculated odds ratios (ORs) (95% confidence intervals (CIs)) to quantify the relationship between initial and mean %HbF with ROP severity (none, stages 1–3).
Results
A total of 42 infants were recruited: mean gestation 28.0 weeks (SD 1.91); mean birth weight 1042 g (SD 264). Six infants died before ROP screening; 14/36 developed ROP (39%); and 22/36 (61%) did not. Infants who developed ROP had similar initial %HbF (83.3 vs 92.3%, P=0.06), but significantly lower mean %HbF (61.75 vs 91.9%, P=0.0001) during their inpatient stay than those who did not develop ROP. In ordinal logistic regression models adjusted for birth weight, gestation and transfusion volume, mean post-natal %HbF was negatively associated with ROP severity: adjusted OR 0.94 (0.90–0.99), while initial %HbF at birth was not: adjusted OR 1.05 (0.97–1.16).
Conclusion
Replacing HbF by HbA during transfusion may promote ROP development by rapidly increasing oxygen availability to the retina. Conversely, maintaining a higher %HbF may be a protective factor against ROP
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