Optimizing the Mulching Pattern and Nitrogen Application Rate to Improve Maize Photosynthetic Capacity, Yield, and Nitrogen Fertilizer Utilization Efficiency.

Residual film pollution and excessive nitrogen fertilizer have become limiting factors for agricultural development. To investigate the feasibility of replacing conventional plastic film with biodegradable plastic film in cold and arid environments under nitrogen application conditions, field experiments were conducted from 2021 to 2022 with plastic film covering (including degradable plastic film (D) and ordinary plastic film (P)) combined with nitrogen fertilizer 0 (N0), 160 (N1), 320 (N2), and 480 (N3) kg·ha-1. The results showed no significant difference (p > 0.05) in dry matter accumulation, photosynthetic gas exchange parameters, soil enzyme activity, or yield of spring maize under degradable plastic film cover compared to ordinary plastic film cover. Nitrogen fertilizer is the main factor limiting the growth of spring maize. The above-ground and root biomass showed a trend of increasing and then decreasing with the increase in nitrogen application level. Increasing nitrogen fertilizer can also improve the photosynthetic gas exchange parameters of leaves, maintain soil enzyme activity, and reduce soil pH. Under the nitrogen application level of N2, the yield of degradable plastic film and ordinary plastic film coverage increased by 3.74~42.50% and 2.05~40.02%, respectively. At the same time, it can also improve water use efficiency and irrigation water use efficiency, but it will reduce nitrogen fertilizer partial productivity and nitrogen fertilizer agronomic use efficiency. Using multiple indicators to evaluate the effect of plastic film mulching combined with nitrogen fertilizer on the comprehensive growth of spring maize, it was found that the DN2 treatment had the best complete growth of maize, which was the best model for achieving stable yield and income increase and green development of spring maize in cold and cool irrigation areas.

Photosynthetic characteristics, yield and quality of sunflower response to deficit irrigation in a cold and arid environment.

In arid regions, deficit irrigation stands as an efficacious strategy for augmenting agricultural water conservation and fostering sustainable crop production. The Hexi Oasis, an irrigation zone situated in Northwest China, serves as a pivotal area to produce grain and cash crops. Nonetheless, due to the predominant conditions of low rainfall and high evaporation, the scarcity of irrigation water has emerged as a critical constraint affecting crop growth and yield in the area. In order to evaluate the effects of deficit irrigation on photosynthetic characteristics, yield, quality, and water use efficiency of sunflower, a two-year field experiment with under-mulched drip irrigation was conducted in the cold and arid environment of the Hexi Oasis region. Water deficits were implemented at sunflower seedling and maturity and consisted of three deficit levels: mild deficit (65-75% field capacity, FC), moderate deficit (55-65% FC), and severe deficit (45-55% FC). A total of six combined water deficit treatments were applied, using full irrigation (75-85% FC) throughout the entire crop-growing season as the control (CK). The results illustrated that water deficit engendered a decrease in leaf net photosynthetic rate, transpiration rate, and stomatal conductance of sunflower compared to CK, with the decrease becoming significant with the water deficit increasing. A mild water deficit, both at the seedling and maturity phases, precipitated a significant enhancement (p< 0.05) in leaf water use efficiency. Under mild water deficit, stomatal limitation emerged as the predominant factor inducing a reduction in the photosynthetic capacity of sunflower leaves, while as the water deficit escalated, non-stomatal limitation progressively assumed dominance. Moreover, a mild/moderate water deficit at seedling and a mild water deficit at maturity (WD1 and WD3) significantly improved sunflower seed quality under consistent yield conditions and significantly increased irrigation water use efficiency, with an average increase of 15.3% and 18.5% over the two years, respectively. Evaluations utilizing principal component analysis and membership function methods revealed that WD1 attained the highest comprehensive score. Consequently, a mild water deficit at both seedling and maturity (WD1) is advocated as the optimal deficit irrigation strategy for sunflower production within the cold and arid environment of Northwest China.

Crop coefficient determination and evapotranspiration estimation of watermelon under water deficit in a cold and arid environment.

To investigate the evapotranspiration and crop coefficient of oasis watermelon under water deficit (WD), mild (60%-70% field capacity, FC)and moderate (50%-60% FC) WD levels were set up at the various growth stages of watermelon, including seedling stage (SS), vine stage (VS), flowering and fruiting stage (FS), expansion stage (ES), and maturity stage (MS), with adequate water supply (70%-80% FC) during the growing season as a control. A two-year (2020-2021) field trial was carried out in the Hexi oasis area of China to explore the effect of WD on watermelon evapotranspiration characteristics and crop coefficient under sub-membrane drip irrigation. The results indicated that the daily reference crop evapotranspiration showed a sawtooth fluctuation which was extremely significantly and positively correlated with temperature, sunshine hours, and wind speed. The water consumption during the entire growing season of watermelon varied from 281-323 mm (2020) and 290-334 mm (2021), among which the phasic evapotranspiration valued the maximum during ES, accounting for 37.85% (2020) and 38.94% (2021) in total, followed in the order of VS, SS, MS, and FS. The evapotranspiration intensity of watermelon increased rapidly from SS to VS, reaching the maximum with 5.82 mm·d-1 at ES, after which it gradually decreased. The crop coefficient at SS, VS, FS, ES, and MS varied from 0.400 to 0.477, from 0.550 to 0.771, from 0.824 to 1.168, from 0.910 to 1.247, and from 0.541 to 0.803, respectively. Any period of WD reduced the crop coefficient and evapotranspiration intensity of watermelon at that stage. And then the relationship between LAI and crop coefficient can be characterized better by an exponential regression, thereby establishing a model for estimating the evapotranspiration of watermelon with a Nash efficiency coefficient of 0.9 or more. Hence, the water demand characteristics of oasis watermelon differ significantly during different growth stages, and reasonable irrigation and water control management measures need to be conducted in conjunction with the water requirements features of each growth stage. Also, this work aims to provide a theoretical basis for the irrigation management of watermelon under sub-membrane drip irrigation in desert oases of cold and arid environments.

A rethinking of collagen as tough biomaterials in meat packaging: assembly from native to synthetic.

Due to the high moisture-associated typical rheology and the changeable and harsh processing conditions in the production process, packaging materials for meat products have higher requirements including a sufficient mechanical strength and proper ductility. Collagen, a highly conserved structural protein consisting of a triple helix of Gly-X-Y repeats, has been proved to be suitable packaging material for meat products. The treated animal digestive tract (i.e. the casing) is the perfect natural packaging material for wrapping meat into sausage. Its thin walls, strong toughness and impact resistance make it the oldest and best edible meat packaging. Collagen casing is another wisdom of meat packaging, which is made by collagen fibers from hide skin, presenting a rapid growth in casing market. To strengthen mechanical strength and barrier behaviors of collagen-based packaging materials, different physical, chemical, and biological cross-linking methods are springing up exuberantly, as well as a variety of reinforcement approaches including nanotechnology. In addition, the rapid development of biomimetic technology also provides a good research idea and means for the promotion of collagen's assembly and relevant mechanical properties. This review can offer some reference on fundamental theory and practical application of collagenous materials in meat products.

Polyphenols and polyphenols-based biopolymer materials: Regulating iron absorption and availability from spontaneous to controllable.

Iron is an important trace element in the body, and it will seriously affect the body's normal operation if it is taken too much or too little. A large number of patients around the world are suffering from iron disorders. However, there are many problems using drugs to treat iron overload and causing prolonged and unbearable suffering for patients. Controlling iron absorption and utilization through diet is becoming the acceptable, safe and healthy method. At present, many literatures have reported that polyphenols can interact with iron ions and can be expected to chelate iron ions, depending on their types and structures. Besides, polyphenols often interact with other macromolecules in the diet, which may complicate this phenols-Fe behavior and give rise to the necessity of building phenolic based biopolymer materials. The biopolymer materials, constructed by self-assembly (non-covalent) or chemical modification (covalent), show excellent properties such as good permeability, targeting, biocompatibility, and high chelation ability. It is believed that this review can greatly facilitate the development of polyphenols-based biopolymer materials construction for regulating iron and improving the well-being of patients.

Effect of Multiple Freeze-Thaw Cycles on Myoglobin and Lipid Oxidations of Grass Carp (Ctenopharyngodon idella) Surimi with Different Pork Back Fat Content.

Fresh grass carp was used to produce surimi and 50 g/kg, 100 g/kg, or 150 g/kg pork back fat was added. The water distribution, thiobarbituric acid reactive substances (TBARS), myoglobin oxidation, color parameter (L*, a*, and b*), heme and non-heme iron content of samples were determined to analyze the effects of different fat content on the oxidation of myoglobin and lipids during multiple freeze-thaw cycles of grass carp surimi. Both multiple freeze-thaw cycles and increased fat content lead to an increase in TBARS, a blue shift in the absorption peak of myoglobin porphyrin, a decrease in heme iron content, and an increase of non-heme iron content. Repeated freeze-thaw caused a decrease in immobilised water content and L*, and caused an increase in a* and b*. Increased fat content caused an increase in immobilised water content, L* and a*, and caused a decrease in b*.

Immunological and anticancer activities of seleno-ovalbumin (Se-OVA) on H22-bearing mice.

Ovalbumin is the main protein component of egg white. Selenium is one of the essential trace elements. In our research, ovalbumin was modified into seleno-ovalbumin. After seleno-modification, the FTIR spectrum of seleno-ovalbumin appeared two new absorption peaks which belonged to the characteristic absorption peaks of Se-O and SeO. Seleno-ovalbumin could reduce the damage of cancer to immune organs, improve the proliferation capacities of T and B lymphocytes, enhance the NK cells cytotoxicity and increase the phagocytic activity of peritoneal macrophages of H22-bearing mice. Besides, Se-OVA could block the cell cycle of solid tumors cells in G0/G1 phase and accelerate the apoptosis of solid tumors cells through mitochondrial pathway.

Using cellulose nanofibers to reinforce polysaccharide films: Blending vs layer-by-layer casting.

Based on the electrostatic interaction mechanism, cellulose nanofiber (CNF) was utilized as reinforcing additives to fabricate polysaccharide films (alginate (Alg) or chitosan (CH)) by two methods: blending and layer-by-layer (LbL). Results showed that the addition of CNF led to higher tensile strength for all films than those without CNF addition, except for the blending CH film due to CNF agglomeration. The highest TS reached 140 MPa for the blending Alg film at 7 wt% CNF. Moreover, all CNF-reinforced films generally had lower water vapor permeability. The addition of CNF aggravated the opacity of all films, especially for the blending ones. Microstructure indicated that CNF were well dispersed in Alg-based films while aggregates were evident in the blending CH films. Interactions between CNF and Alg (or CH) and their relations on film performance were supported by FTIR and DSC of the resultant films, zeta-potential and turbidity of the film-forming solutions.

A top-down approach to improve collagen film's performance: The comparisons of macro, micro and nano sized fibers.

The severe reduction of mechanical strength of collagen once it is extracted or dissociated from animal tissues and no additional crosslinking approaches are conducted, impede its application in biodegradable and edible food packaging. Here, for the first time, high pressure homogenization (HPH) was used to prepare diverse sized fibers and the related fibers-composed films' performance were investigated. These fibers have a diversity of effects on film performance. The films prepared with smaller sized fibers had a more uniform and denser structure. The mechanical and the water barrier properties of the films improved significantly as the fiber size decreased. No obvious change in FTIR and thermal properties suggests that the improved film performance is mainly attributed to the physical entanglement and non-covalent bonds. Given the forementioned benefits of the films, control of fiber size can be a potential industrial approach for producing collagenous materials in edible food packaging.

An Attempt of Using ß-Sitosterol-Corn Oil Oleogels to Improve Water Barrier Properties of Gelatin Film.

Oleogel with tailored viscoelasticity is a great interest for food structuring, while its potential benefits for edible film performance are not clear. In this study, ß-sitosterol (0, 5, 10, 15, and 20 wt%)-corn oil oleogel was developed and used in the formation of gelatin-based films. Importantly, adding oleogel significantly decreased water vapor permeability of the gelatin films, however, it had little negative influence on film strength. In addition, the results of this study demonstrated that increasing the sitosterol in oleogels led to an increasing number of ordered crystals formed in the oleogel, which contributed to compact and smooth surface of the film. Moreover, the incorporation of oleogel also caused some changes in molecule conformation and film barrier property. Therefore, the superior mechanical performance and moisture resistance properties of the film were obtained when 15% ß-sitosterol was used to prepare oleogel. PRACTICAL APPLICATION: Corn oil oleogels ß-sitosterol was incorporated with gelatin to prepare the gelatin film aiming to improve the water resistance of the films for its variety of practical production. The enhanced vapor permeability and accepted strength of the emulsion film indicated the potential application of it with a variety of edible packaging forms, such as films, pouch and sachet in medium and high humid condition.

Mechanical reinforcement of gelatin hydrogel with nanofiber cellulose as a function of percolation concentration.

Given a variety of distinguished aspect ratio-related characteristics of nanofiber cellulose (NFC), the impact of NFC on gelatin hydrogel performance involving strength, rheology, microstructure was investigated, focusing on concentration percolation mechanism for it. The inner topography displayed a compact three-dimensional network structure in the NFC-added gelatin gel, however, an NFC amount of 7.5gkg-1 caused more inhomogeneous aggregation. Texture profile analysis showed that the addition of NFC increased the hardness but reduced the elasticity of gelatin gel at 10°C, depending on NFC concentration. For static rheology, adding NFC transformed gelatin solution from the Newtonian action into pseudoplastic behavior at 60°C, with a marked increase of viscosity. Furthermore, NFC improved the temperature of sol-gel transition of gelatin, even no obvious transformation as ≥5gkg-1 NFC used. NFC reinforcement provides the potential to use as texture modifier along with gelatin in food field.

Composition of Lycium barbarum polysaccharides and their apoptosis-inducing effect on human hepatoma SMMC-7721 cells.

BACKGROUND: Lycium barbarum polysaccharide (LBP) is a natural functional component that has a variety of biological activities. The molecular structures and apoptosis-inducing activities on human hepatoma SMMC-7721 cells of two LBP fractions, LBP-d and LBP-e, were investigated. RESULTS: The results showed that LBP-d and LBP-e both consist of protein, uronic acid, and neutral sugars in different proportions. The structure of LBP was characterized by gas chromatography, periodate oxidation, and Smith degradation. LBP-d was composed of eight kinds of monosaccharides (fucose, ribose, rhamnose, arabinose, xylose, mannose, galactose, and glucose), while LBP-e was composed of six kinds of monosaccharides (fucose, rhamnose, arabinose, mannose, galactose, and glucose). LBP-d and LBP-e blocked SMMC-7721 cells at the G0/G1 and S phases with an inhibition ratio of 26.70 and 45.13%, respectively, and enhanced the concentration of Ca(2+) in the cytoplasm of SMMC-7721. CONCLUSION: The contents of protein, uronic acid, and galactose in LBP-e were much higher than those in LBP-d, which might responsible for their different bioactivities. The results showed that LBP can be provided as a potential chemotherapeutic agent drug to treat cancer.

Role of liver fatty acid binding protein in hepatocellular injury: effect of CrPic treatment.

This study was designed to investigate the molecular mechanisms of chromium picolinate (CrPic, Fig. 1) hepatoprotective activity from alloxan-induced hepatic injury. Diabetes is induced by alloxan-treatment concurrently with the hepatic injury in mice. In this study, we investigate the protective effect of CrPic treatment in hepatic injury and the signal role of liver fatty acid binding protein in early hepatocellular injury diagnostics. In this study, alanine aminotransferase (ALT; EC 2.6.1.2) and aspartate aminotransferase (AST; EC 2.6.1.1) levels in the alloxan group were higher 71% and 50%, respectively, than those of the control group (ALT: 14.51±0.74; AST: 22.60±0.69). The AST and ALT levels in CrPic group were of minimal difference compared to the control groups. Here, CrPic exhibited amelioration alloxan induced oxidative stress in mouse livers. A significant increase in liver fatty acid-binding protein (L-FABP) was observed, which indicates increased fatty acid utilization in liver tissue [1]. In this study, the mRNA levels of L-FABP increased in both the control (1.1 fold) and CrPic (0.78 fold) groups compared the alloxan group. These findings suggest that hepatic injury may be prevented by CrPic, and is a potential target for use in the treatment of early hepatic injury.

Hepatoprotective activity of CrPic against alloxan-induced hepatotoxicity in mice.

This study focused on oxidation hepatic injury induced by alloxan treatment in mice and the hepatoprotective effect of chromium picolinate (CrPic) against such injury. The mice were randomly divided into three groups (control, alloxan, and CrPic). The CrPic mice were given Cr(3+) (40 µg/kg bm/day), and other mice were given equivalent intragastric doses of water every day. After 4 weeks, the groups alloxan and CrPic were treated with alloxan (40 mg/kg/day) through intraperitoneal injection daily for 6 days. Biochemical and enzymatic characteristics were assayed in these animals. The MDA levels of the control and CrPic groups were 33.93 % and 28.45 % lower, respectively, than that of the alloxan group. The levels of superoxide dismutase (SOD) and GSH-Px in the alloxan group were 15.30 % and 15.69 % higher, respectively,than those of the control group. Both the SOD and GSH-Px levels of the control and CrPic groups were about the same. Levels of CuZnSOD mRNA of the control and CrPic groups were 0.27 fold and 1.03 fold lower than in the alloxan group. The transcription levels of GSH-Px in the control and CrPic groups were 1.57 fold and 0.99 fold below those of the alloxan group. These results show that significant hepatic injury can be induced by alloxan treatment in mice; in addition, CrPic may be useful in health products meant to treat human liver disease.