Insight into the mechanisms of combining direct current magnetic field with phosphate in promoting emulsifying properties of myofibrillar protein.

This study investigated the combined effects of direct-current magnetic field (DC-MF, 9.5 mT) and tetrasodium-pyrophosphate (TSPP, 1-5 g/L) on emulsified gel properties of porcine myofibrillar protein (MP). Results showed that MP at DC-MF and 3 g/L TSPP had decreased spectrum intensity of UV and fluorescence compared to that without DC-MF, owing to the changes of MP tertiary structure caused by DC-MF, especially tryptophan and tyrosine. The emulsion treated with DC-MF behaved better emulsifying activity and stability than that without DC-MF under such condition. And emulsion had lower creaming index and better storage stability. Gels prepared by this MP emulsion had low porosity and stable structure, accompanying with smaller size and more uniform distribution of oil droplets. Microstructure images showed that gels were covered with microporous structure, which was conducive to the good WHC of the emulsified gels (97.12%). These results showed the feasibility of DC-MF and TSPP in improving MP emulsion/emulsified gel.

Effect of magnetic field mediated CaCl2 on the edible quality of low-sodium minced pork gels.

Magnetic field combined with calcium chloride (CaCl2,) treatment is a highly promising technique for reducing sodium chloride (NaCl) in meat. Therefore, this paper investigated the effect of reducing NaCl addition (0-10%) by CaCl2 in combination with a magnetic field (3.8 mT) on the edible quality of low-salt pork mince. It is desired to drive the application of magnetic field and CaCl2 in low-sodium meat processing in this way. Results showed that the cooking yield, color, hardness, elasticity, mouthfeel, apparent texture, and orderliness of protein conformation of all minced pork were improved as compared to the control group, while the electron nose response values of their volatile sulfides and nitrogen oxides were decreased. In particular, the best edible quality and perceived salty intensity of minced pork gel was obtained by using CaCl2 in place of 5% NaCl under magnetic field mediation. In addition, energy dispersive X-ray spectroscopy scans showed that the reduced NaCl treatment by magnetic field combined with CaCl2 could increase the signal intensity of sodium in minced pork matrices to some extent. Magnetic field-mediated substitution of NaCl for CaCl2 treatment was also found to be favorable for inducing the transition of the protein secondary structure from an irregularly coiled to a ß-folded structure (demonstrated by infrared spectroscopy). In short, magnetic fields combined with CaCl2 instead of NaCl was a highly promising method of producing low-NaCl meats.

Effect and mechanism of DC magnetic field combined with calcium chloride on saltiness and flavor enhancement of low salt pork gel.

This study intended to investigate the synergistic effect of direct current magnetic field (DC-MF) and calcium chloride (CaCl2) on improving the saltiness and quality of pork gel and to explore the potential adjustment mechanisms involved. Pork mince was subjected to low-salt treatment of DC-MF for 3 h (T1), CaCl2 substitution (T2) or DC-MF combined with CaCl2 (T3) respectively under high and low salt controls (HC and LC). Heat-induced gels of pork mince were prepared and analyzed in terms of gel texture, saltiness perception, moisture status, salt release and protein structure. Results indicated that DC-MF combined with CaCl2 treatment could reduce the addition of sodium chloride by 5% while maintaining the saltiness and overall acceptability of mince as well as improving its texture and yield. Further studies revealed that DC-MF in concert with CaCl2 treatment could not only increase the moisture content of mince gel, but also enhance saltiness perception by causing gel matrix to release salt-bearing juices under external forces. The energy spectrum analysis also illustrated that co-treatment technique could avoid the salt loss of minced meat during cooking process. Finally, a possible potential regulatory mechanism was speculated that the synergistic action of DC-MF and CaCl2 could alter the gel texture and sodium salt availability by modifying protein conformation and inducing a competitive binding reaction site for calcium and sodium ions. In conclusion, synergistic treatment by DC-MF and CaCl2 was a potential strategy in meat salt reduction.

Can the Policy of Increasing Retirement Age Raise Pension Revenue in China-A Case Study of Anhui Province.

With gradual progress in the medical field and the rising living standard of people, the life expectancy of people is gradually increasing. Unfortunately, this positive development contributes significantly to the aging of societies and creates huge challenges for pension systems. In order to mitigate the pressure on its pension system in the coming years, China is considering increasing the retirement age, just like many other countries. Based on the wage data of urban employees, pension revenue and expenditure data of employees in Anhui Province over the years, we constructed a model to predict average wages and forecast the revenue of the urban pension system from 2022 to 2032. We predicted the pension revenues by simulating an adjusted retirement age under two different schemes. The results of the study showed that the policies of appropriately increasing the retirement age can raise pension revenue. Compared with a one-step retirement age change scheme, a rolling retirement age change scheme that increases the retirement age by several months each year was found to be more suitable for the healthy development of the pension system.

Effect of sarcoplasmic proteins oxidation on the gel properties of myofibrillar proteins from pork muscles.

This study investigated the influence of sarcoplasmic proteins (SPs) treated by the oxidation system (0.1 mmol/L FeCl3 , 0.1 mmol/L ascorbic acid, and 0, 1, 5, 10 mmol/L H2 O2 ) on the properties of pork myofibrillar proteins (MPs) gel. After oxidation treatment, the SPs showed an increased in carbonyl content and a decreased in total sulfhydryl content, coupled with the cross-linking of protein components by disulfide bonds and covalent bonds. The MPs gel with SPs oxidized at 1 mmol/L H2 O2 exhibited the maximal strength while the minimal water holding capacity (WHC). The WHC of MPs gel was significantly decreased with increasing SPs oxidation, leading to the increase of free water and the decrease of immobilized water in the gel system. The microstructures of MPs gels with moderately (1 mmol/L H2 O2 ) oxidized SPs showed a more compact and smaller pore gel network than MPs alone, suggesting adding oxidized SPs can expel water trapped in the gel. Furthermore, the environmental polarity of aliphatic C-H groups increased with SPs oxidation.

Low frequency magnetic field plus high pH promote the quality of pork myofibrillar protein gel: A novel study combined with low field NMR and Raman spectroscopy.

This study investigated the combined effects of low frequency magnetic field (LF-MF) (3.8 mT) and pH (5-7) on pork myofibrillar protein (MP) gel quality. With LF-MF applying, the water ratio and migration rate both changed to varying extents. LF-MF modified secondary structure of MP by exposing tryptophan and tyrosine residues to participate in hydrogen bonding with water, as well changing α-helix and ß-sheet to varying extents; LF-MF also drove molecular rearrangement and crosslinking. LF-MF brought gel larger and more ordered network to trap more water. And the water holding capacity of gels significantly increased by 2.50% and 2.47% when LF-MF involved at appropriate pH (pH 6.5 and 7.0). Collectively, our results support an optimum treatment (pH 6.5 or 7.0 with applying LF-MF) for the improvement in gel quality of pork MP, and the combination of physical and chemical treatments casts a new light into improving product quality during meat processing.

Gel properties of myofibrillar proteins heated at different heating rates under a low-frequency magnetic field.

The effects of low-frequency magnetic field combined with different heating rates on pork myofibrillar protein (MP) gels were investigated. Samples were treated under different heating rates (1 °C/min and 2 °C/min) in the presence or absence of 9.5 mT low-frequency magnetic field. The highest levels of intermolecular and intramolecular ionic and hydrogen bonds in MP were observed at the heating rate of 2 °C/min under the 9.5 mT magnetic field. These bonds resulted in decreasing the α-helix and increasing the ß-sheet and ß-turn, which promoted the formation of a more uniform microstructure. It also increased the proportion of bound water, increasing the ability of MP to bind with water. This effect, combined with the weaker hydrophobic interactions, as confirmed by the reduced content of tryptophan and aliphatic residues, explained well the high water-holding capacity of MP induced by heating at 2 °C/min under the 9.5 mT magnetic field.

Low frequency magnetic fields modification on hydrogen peroxide oxidized myoglobin-isolate and mechanisms underlying the chain reaction process.

The effects of low frequency magnetic field (0-12 mT) on hydrogen peroxide oxidized myoglobin-isolate (MbI) were investigated. The results indicate that the primary target of the hydrogen peroxide oxidation was Met(FeIII)Mb, leading to the fall off of iron ions from the porphyrin ring. Additionally, the increased magnetic field (≥9 mT) enhanced the release of more iron ions to react with H2O2, giving rise to the production of more hydroxyl radicals and the shift of oxidation site from porphyrin ring to Mb skeleton. Moreover, the directional movement of iron ions induced by magnetic field caused the generation of local micro-electric field and the rearrangement of charged groups on the protein surface or near-surface, thus affecting Mb aggregation. Overall, the magnetic field interfered with the hydrogen peroxide chain reaction process, changed the redox equivalents of Mb, and shifted the oxidation sites of Mb.

Effects of low frequency magnetic field on myoglobin oxidation stability.

The effects of low frequency magnetic field on myoglobin (Mb) oxidation stability were evaluated by treatments at 0, 3, 6, 9, 12 mT and storage for 10 h. The results showed that Mb oxidation was inhibited under all magnetic field treatments, due to the increase of total sulfhydryl and free amino groups (9 or 12 mT) from unfolding of Mb clusters (3, 9, 12 mT) as well as ß-turn and ß-sheet structures (9 or 12 mT). The unfolding also induced (i) the destruction or burial of iron porphyrin and tyrosine residues; (ii) the exposure of tryptophan; (iii) more uniform Mb particle size distribution (3, 9, 12 mT) and increased zeta potential (3, 6, 12 mT). Overall, magnetic field promoted exposed active groups as the preferred oxidation target, thus decreasing the oxidation rate of central iron atoms. It also promoted Mb stability by redistributing particle size and increasing zeta potential.

Effect of low-frequency magnetic field on the gel properties of pork myofibrillar proteins.

This study aimed to investigate the effect of a low-frequency magnetic field (LF-MF; 0, 0.25, 0.5, and 1.4 mT) on the gel properties of pork myofibrillar protein (MP) and to explore potential mechanisms. The water-holding capacity (WHC) and rheological properties of MP gels treated at 0.5 mT were better than those from other treatments. The water mobility did not change significantly as intensity increased, while the ratios of immobilized water (PT21) and free water (PT22) significantly decreased and increased, respectively. This suggested that the effect of LF-MF on MP hydration might be related to the formation of water clusters. Raman spectra suggested that α-helices unfolded and ß-sheets, ß-turns, and random coils were formed in MP gels (from 0.25 to 1.4 mT). Furthermore, the intensities of characteristic peaks in the tryptophan and aliphatic residues band were highest at 0.5 mT, indicating that 0.5 mT was the optimum intensity for hydrophobic interactions.

[Epidemiological characteristics of imported malaria cases in Neijiang City, 2013].

OBJECTIVE: To understand the epidemiological characteristics of imported malaria cases in Neijiang City in 2013, so as to provide the references for malaria elimination in the city. METHODS: The epidemiological data of malaria cases were collected from the Parasitic Diseases Information Management System of Chinese Center for Disease Control and Prevention, and the data were analyzed with the descriptive epidemiological method. RESULTS: Totally 19 cases of imported malaria cases were reported in Neijiang City in 2013, which was increased by 375% comparing to that in 2012 (4 cases) , and all the cases were confirmed by the laboratory. Among these cases, 14 were (73.68%) falciparum malaria cases, 5 (26.32%) were vivax malaria cases; 13 cases (68.42%) were from African countries, and the other 6 (31.58%) were from Southeast Asia. These cases were distributed throughout each quater, which had no significant seasonality. All the cases were male aged from 20-49 years, and the majority of them (16 cases, 84.21%) were farmers and workers. CONCLUSIONS: The prevention and control situation of imported malaria is severe in Neijiang City. The capacity construction of malaria diagnosis and treatment of basic medical institutions as well as the health education and monitoring and management to floating population should be strengthened.

The clinical value of LRRC3B gene expression and promoter hypermethylation in breast carcinomas.

Epigenetic alteration of tumor suppressor genes by promoter hypermethylation has played a key role in tumorigenesis, which is an important mechanism as indispensable as gene deletion and mutation. LRRC3B is a potential tumor suppressor gene newly discovered; however, the specific biologic function is still unknown. In the present study, we tested the expression levels of LRRC3B by methods associated with immunohistochemistry, Real-Time PCR, and methylation-specific polymerase chain reaction. Results showed that the expression levels were significantly low irrespective of methylation status, suggesting that there were other factors involved in this process. However, the expression profile of LRRC3B had a significant relationship with tissue grade, irrespective of the expressions of PR, CERB-2, VEGF, and Ki67 except in cases of p53 and ER, leading us to a conclusion that the abnormal expression of LRRC3B could serve as a useful marker for diagnosis and prognosis in breast carcinomas.

Novel compound PS-101 exhibits selective inhibition in non-small-cell lung cancer cell by blocking the EGFR-driven antiapoptotic pathway.

This study investigated the anticancer effect of a novel compound PS-101 in human lung cancer cells. By phenotype screening, PS-101 exhibited highly selective inhibition in EGFR-overexpressed non-small cell lung cancer cells NCI-H460 and A549 while displaying no obvious toxicity to normal hepatic cell HL-7702, lung fibroblast cell WI-38, liver cancer cell BEL-7404 and gastric cancer cell MCG-803. A combination of cell viability assay, immunoblotting, and RNA interference revealed that PS-101 induced EGFR-dependent inhibition selectivity. Further studies showed that PS-101 caused cell cycle arrest at G1 phase, changed cell size, induced apoptosis and led to cell death by increasing the proportion of sub-G1 cells. Molecular mechanism studies suggested that blocking the EGFR-driven antiapoptotic pathway is essential for PS-101-induced apoptosis. The contribution of blocking the EGFR-driven antiapoptotic pathway was verified through examines abundance of likely candidate proteins and RNA interference. The root cause for increase in BAD and decrease in Bcl-2 which altogether initiated caspase-dependent apoptosis were predominantly due to down-regulation the expression of EGFR after PS-101 treatment. PS-101 strongly down-regulated the EGFR expression to trigger proapototic protein BAD increase and antiproapototic protein Bcl-2 decrease, which altogether actived effector caspase-3/9 to initiate cell apoptisis. Taken together, these results suggest that PS-101 may be a potential candidate for cancer therapy against human lung cancer.