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The effects of immersion freezing and air freezing at different temperatures (-18 and -38 ℃) on the quality of braised beef with potato were studied by physicochemical measurements, microstructural observation and sensory evaluation. The results showed that freezing at -38 ℃ maintained better quality of braised beef with potato compared with freezing at -18 ℃, and immersion freezing was significantly superior to air freezing. The freezing time of beef and potato in the dish under -38 ℃ immersion freezing was shortened by 96.02% and 97.34%, respectively, compared with air freezing at -18 ℃, and the time required to pass through the maximum ice crystal formation zone for beef and potato was 9.67 and 10.92 min, respectively, suggesting improved freezing rate of the dish. Under this condition, the L*, a* and b* values of beef and potato were closer to those of the unfrozen dish; the hardness and elasticity of beef were significantly higher than those of the other frozen treatment groups (P < 0.05), and the shear force was 25.35 N, which was closer to that of the unfrozen sample (26.70 N), indicating good toughness of beef; the hardness of potato was 341.95 g, which was significantly higher than that of (P < 0.05) air-frozen samples, indicating good texture. Scanning electron microscopy (SEM) showed that beef muscle fibers were not broken after immersion freezing at -38 ℃, the gap between muscle fiber bundles was the smallest, arranged in an orderly manner; the cell contour of potato was clear and compact. The overall sensory score of the immersion-frozen sample was higher than that of the air-frozen one, and the sensory scores of beef and potato in the dish after -38 ℃ immersion freezing were 88.80 and 86.80 points, respectively, indicating higher acceptability. These findings provide a theoretical basis for the development of freezing preservation technologies for industrialized Chinese dishes.

Melanoma is one of the most dangerous tumors due to its high-grade malignancy. Though patients in early stage can be completely cured by surgery, for high-risk cases (stage ⅡB-Ⅳ), adjuvant therapy is of great importance to prolong the survival and improve the prognosis. In recent years, thanks to the booming development of systemic regimen, the perioperative managements for stage Ⅲ cases have been continuously evolving. In the current paper, we focused on the role of lymph node biopsy and surgical resection, postoperative adjuvant therapy options, as well as the cutting-edge neoadjuvant therapy development, aiming to provide new perioperative strategies for stage Ⅲ melanoma patients.

A class of aliphatic short chain nitrocompounds have been reported as being capable of CH4 reduction both in vitro and in vivo. However, the laboratory evidence associated with the metabolic fate of nitrocompounds in the rumen has not been well documented. The present study was conducted to compare in vitro degradation and metabolism of nitroethane (NE), 2-nitroethanol (NEOH), and 2-nitro-1-propanol (NPOH) incubated with mixed rumen microorganisms of dairy cows. After 10 mM supplementation of nitrocompounds, a serious of batch cultures were carried out for 120 h under the presence of two substrates differing in the ratio of maize meal to alfalfa hay (HF, 1:4; LF, 4:1). Compared to the control, methane production was reduced by 59% in NPOH and by >97% in both NE and NEOH, and such antimethanogenic effects were more pronounced in the LF than the HF group. Although NE, NEOH, and NPOH addition did not alter total VFA production, the rumen fermentation pattern shifted toward increasing propionate and butyrate and decreasing acetate production. The kinetic disappearance of each nitrocompound was well fitted to the one-compartment model, and the disappearance rate (k, %/h) of NE was 2.6 to 5.2 times greater than those of NEOH and NPOH. Higher intermediates of nitrite occurred in NEOH in comparison with NPOH and NE while ammonia N production was lowest in NEOH. Consequently, a stepwise accumulation of bacterial crude protein (BCP) in response to the nitrocompound addition was observed in both the HF and LF group. In brief, both NE and NEOH in comparison with NPOH presented greater antimethanogenic activity via the shift of rumen fermentation. In addition, the present study provided the first direct evidence that rumen microbes were able to cleave these nitrocompounds into nitrite, and the subsequent metabolism of nitrite into ammonia N may enhance the growth of rumen microbes or promote microbial activities. [ABSTRACT FROM AUTHOR]

To study the pollution characteristics of atmospheric heavy metal elements in a living area of Zhengzhou City, assess the potential ecological risks, and determine risks to resident health in this city, the Wuhan Tianhong TH-16A Airborne Particles Intelligent Sampler was used to collect atmospheric PM 2.5 in Zhengzhou City. The mass concentrations of 17 metal elements were analyzed by ambient air determination of inorganic elements by ambient particle matter wavelength dispersive X-ray fluorescence spectrometry. The source of heavy metals was analyzed by the enrichment factor method and principal component analysis. The ecological risk index method and the US Environmental Protection Agency's health risk assessment method were used to evaluate the potential ecological risks and residents' health risks from Cr, Cd, Cu, Zn, Ni, Pb, As, and other elements. The results showed that metals with higher enrichment factor values were Cd, Sb, Pb, and As, and Cd had the highest enrichment factor value. The sources of metal elements in a living area of Zhengzhou City were mainly crust/burning coal, fuel, garbage burning, metallurgical dust, and vehicle emission. The single factor potential ecological hazard index values of Cd, Pb, Zn, As, Cu, Ni, and Cr were 70420.2, 255.3, 204.6, 71.5, 36.9, 24.0, and 5.1, respectively. Cd, As, and Cr in a living area of Zhengzhou City posed a cancer risk, and Cd was the most harmful. Mn had a non-carcinogenic risk.

The three typical carbon enterprises in Zhengzhou were selected as research targets, and the emission characteristics of volatile organic compounds (VOCs) and their ozone formation potential (OFP) in different functional areas were studied. The US Environmental Protection Agency (EPA) health risk assessment model was used to evaluate the health risks of VOCs emitted by the carbon industry. The results showed that the concentration of VOCs in the production areas of the three research enterprises was between 89.77-964.60 μg·m -3 , and the management area was between 51.46-121.59 μg·m -3 . Naphthalene and carbon disulfide were at the highest concentrations in the carbon plants. The ozone formation potential of VOCs in the production area was between 75.42-1416.73 μg·m -3 , and in the management area was between 65.32-202.42 μg·m -3 , mainly from the contribution of aromatic hydrocarbons and olefins. The carcinogenic health risk (Risk) of VOCs in the production area was 3.5×10 -5 -2.8×10 -3 , and in the management area was 2.0×10 -5 -9.4×10 -5 , which was higher than the maximum acceptable level recommended by the EPA (10 -6 ). The non-carcinogenic health risk index (HI) of the VOCs in the production area was 3.2-1.4×10 2 , and in the management area was 4.3×10 -1 -3.8, except for the management area of the first enterprise, which was greater than 1, which may expose the workers. These health factors cause cancer and non-carcinogenic hazards.