Analysis of soil fertility and its anomalies using an objective model

In this work, the use of an objective method, the formulation of the Rasch measurement model, which synthesizes data with different units into a uniform analytical framework, is considered to get representative measures of soil fertility potential in an experimental field. Thus, two types of information about the soil were obtained from soil samples taken at 70 locations: first, the textural components were determined, and, secondly, deep (ECa‐90) and shallow (ECa‐30) soil apparent electrical conductivity, approximately 0–90 and 0–30 cm depths, respectively, were measured. A latent variable, denominated soil fertility potential, was defined. It is supposed, and later it is verified, that all soil properties previously indicated have a marked influence on the latent variable. The adequate assignment of categorical values across properties measures and the good fit of the data are checked as a previous phase to properly compute the Rasch measures. After applying the Rasch methodology, it was obtained that both electrical conductivities are the most influential properties on soil fertility potential, getting moreover a ranking of all soil samples according to their fertility potential and the unexpected behaviors, called misfits, of some soil samples, which constitute a very useful information to better match soil and crop requirements as they vary in the field, being a rational basis for a site‐specific crop management.     

不同类型玉米籽粒淀粉积累、相关酶活及基因表达差异分析

为探究不同类型玉米淀粉形成机理,对普通玉米、甜玉米、糯玉米淀粉积累、相关酶活及基因表达进行测定,分析不同类型玉米淀粉积累、相关酶活及基因表达之间的差异及相互关系。结果表明,不同类型玉米总淀粉和直链淀粉百分含量为:普通玉米>糯玉米>甜玉米,支链淀粉百分含量为:糯玉米>普通玉米>甜玉米,灌浆期间总淀粉和直链淀粉含量3个玉米类型间差异显著;灌浆期间,普通玉米各淀粉合成相关酶活性最高,甜玉米淀粉合成相关酶活性最低,糯玉米则介于普通玉米和甜玉米之间,但其GBSS酶活性很小。灌浆期间3个类型玉米除GBSS酶活性差异不显著外,其他淀粉合成相关酶活性差异显著;普通玉米淀粉合成相关基因表达量总体均高于甜玉米和糯玉米,甜玉米和糯玉米相关突变基因仍存在表达。表明不同类型玉米淀粉含量和组成上差异明显;普通玉米淀粉的形成需要淀粉合成相关酶相互作用,淀粉合成相关酶活性的缺失会改变淀粉组成;不同类型玉米淀粉合成相关基因表达差异显著,但都存在转录活性。对普通玉米进行相关性分析同时发现,淀粉的合成不仅受到转录调控,还受到转录后调控,淀粉的合成是淀粉合成各酶之间相互协调的结果。     

血细胞浓度对猪血豆腐品质的影响

为探明血细胞浓度对猪血豆腐品质的影响,以生理盐水替代部分血细胞的方法调整原血中血细胞浓度,并分析不同血细胞浓度的猪血制成的猪血豆腐样品的质构、感官、色泽和持水性品质.结果表明:随着血细胞浓度的降低,猪血豆腐的硬度显著降低,破裂力和剪切力先增大后减小,红度a*值和黄度b*值随血细胞浓度减小而降低,持水性随血细胞浓度降低先减小后增大.降低猪血中血细胞浓度能够显著改善猪血豆腐的口感品质,血细胞浓度在0.68×109～2.80×109个/mL时,血豆腐的总体接受度最高.     

Synthesis,Structural and Pharmacological Characterizations of CIC,a Novel α-Conotoxin with an Extended N-Terminal Tail

Cone snails are venomous marine predators that rely on fast-acting venom to subdue their prey and defend against aggressors. The conotoxins produced in the venom gland are small disulfide-rich peptides with high affinity and selectivity for their pharmacological targets. A dominant group comprises α-conotoxins, targeting nicotinic acetylcholine receptors. Here, we report on the synthesis, structure determination and biological activity of a novel α-conotoxin, CIC, found in the predatory venom of the piscivorous species Conus catus and its truncated mutant Δ-CIC. CIC is a 4/7 α-conotoxin with an unusual extended N-terminal tail. High-resolution NMR spectroscopy shows a major influence of the N-terminal tail on the apparent rigidity of the three-dimensional structure of CIC compared to the more flexible Δ-CIC. Surprisingly, this effect on the structure does not alter the biological activity, since both peptides selectively inhibit α3β2 and α6/α3β2β3 nAChRs with almost identical sub- to low micromolar inhibition constants. Our results suggest that the N-terminal part of α-conotoxins can accommodate chemical modifications without affecting their pharmacology.     

Cyanobacteria—From the Oceans to the Potential Biotechnological and Biomedical Applications

Cyanobacteria are photosynthetic prokaryotic organisms which represent a significant source of novel, bioactive, secondary metabolites, and they are also considered an abundant source of bioactive compounds/drugs, such as dolastatin, cryptophycin 1, curacin toyocamycin, phytoalexin, cyanovirin-N and phycocyanin. Some of these compounds have displayed promising results in successful Phase I, II, III and IV clinical trials. Additionally, the cyanobacterial compounds applied to medical research have demonstrated an exciting future with great potential to be developed into new medicines. Most of these compounds have exhibited strong pharmacological activities, including neurotoxicity, cytotoxicity and antiviral activity against HCMV, HSV-1, HHV-6 and HIV-1, so these metabolites could be promising candidates for COVID-19 treatment. Therefore, the effective large-scale production of natural marine products through synthesis is important for resolving the existing issues associated with chemical isolation, including small yields, and may be necessary to better investigate their biological activities. Herein, we highlight the total synthesized and stereochemical determinations of the cyanobacterial bioactive compounds. Furthermore, this review primarily focuses on the biotechnological applications of cyanobacteria, including applications as cosmetics, food supplements, and the nanobiotechnological applications of cyanobacterial bioactive compounds in potential medicinal applications for various human diseases are discussed.     

不同枇杷品种果实发育过程中果肉细胞壁组分的研究

探讨不同发育时期,细胞壁组分的变化对不同品种枇杷果肉质地的影响。以果肉质地差异较大的‘解放钟’(Eriobotrya japonica Lindl. cv. Jiefangzhong)和‘白梨’枇杷(Eriobotrya japonica Lindl. cv. Baili)为试材,分析果实在生长发育过程中细胞壁组分的变化,分析果肉质地差异性与细胞壁成分之间的相关性。结果表明,果实生长发育过程中,‘解放钟’和‘白梨’枇杷果肉水溶性果胶(water soluble pectin, WSP)含量均呈上升趋势;离子结合果胶(Ionic bound pectin, ISP)、共价结合果胶(covalently bound pectin, CSP)、纤维素(Cellulose)、半纤维素(semi-cellulose)、总钙和氯化钠溶性钙含量均呈下降趋势。在果实发育后期,‘解放钟’果肉WSP和细胞壁离子结合蛋白含量显著高于‘白梨’(P<0.05),但两者的细胞壁共价结合蛋白含量差异不大。‘解放钟’果肉纤维素含量始终高于‘白梨’且差异达显著水平(P<0.05),而果肉半纤维素含量差异不显著(P>0.05)。WSP、ISP、CSP、纤维素、半纤维素、离子结合蛋白与枇杷果肉质地形成相关,WSP、纤维素和离子结合蛋白是形成‘解放钟’和‘白梨’枇杷果肉质地差异的主要因素。     

2种日粮对不同生长阶段乌金猪脂肪组织脂类合成代谢相关基因表达的影响

为探讨不同日粮对乌金猪不同生长阶段脂类合成代谢相关基因表达的影响,试验选取体重约23 kg乌金猪36头,公、母各半,随机分为2个处理组,每个处理组3个重复,每个重复6头。处理1组饲喂乌金猪日粮,处理2组饲喂NRC日粮。分别于30、60和100 kg体重时屠宰,通过Real-time PCR比较研究3个脂肪合成代谢相关基因在脂肪组织中表达的差异。结果显示,体重30 kg时,处理1组脂肪酸合成酶(fatty acid synthase,FAS)的相对表达量显著低于处理2组(P<0.05),60和100 kg时,处理1组FAS基因的相对表达量高于处理2组,60 kg时达到显著水平(P<0.05);在各个体重时,处理1组固醇调节元件结合蛋白1c(sterol regulator element binding protein-1c,SREBP-1c)的相对表达量均高于处理2组,30和60 kg时达到显著水平(P<0.05);在各个体重时,处理1组二酰基甘油酰基转移酶1(diacylglycerol acyltransferase-1,DGAT-1)的相对表达量低于处理2组,100 kg时达到显著水平(P<0.05)。提示,不同日粮调控不同体重乌金猪脂类合成代谢相关基因表达存在着差异。     

Low-Dose X-Ray Treatment of Fresh Channel Catfish Fillets Does Not Affect Color,Texture, or Oxidation

Consumer uncertainty of irradiated food products has slowed implementation of food irradiation, even though it has been proven as a safe and effective technology. For acceptance, irradiated products should not be distinguishable from alternatively processed products. The present research was designed to determine if X-ray irradiation treatment results in changes in selected quality parameters (color, texture, and oxidation) of fresh aquacultured channel catfish fillets. Fillets (Ictalurus punctatus) were treated to 0, 0.5, 1.0, and 1.5 kGy using an X-ray irradiator and stored at 3°C for 17 days. Periodically during storage, samples were removed and instrumentally measured for color, texture, and oxidation (thiobarbituric acid reactive substances). Color, texture, and oxidation did not change (p > 0.05) over time or with irradiation dose. Results indicated that low-dose X-ray treated raw catfish fillets were not distinguishable from untreated controls.     

Control of Lipid Oxidation and Texture Changes in Frozen Sardine Mince by Combined Use of Milk Protein Concentrate and Caffeic Acid

The effectiveness of milk protein concentrate (MPC) and caffeic acid in controlling lipid oxidation and texture changes in 6-month frozen stored sardine mince was investigated using two different concentrations of caffeic acid (200 and 400 ppm) with and without MPC (4%). The extent of lipid oxidation was monitored by measuring thiobarbituric acid reactive substances (TBARS) while changes in the texture of mince due to frozen storage were assessed using Texture Analyzer (TA.XT Plus) and sensory analysis. Cooking loss upon frozen storage was also determined. The addition of MPC and/or caffeic acid significantly reduced lipid oxidation throughout the storage period. However, neither added benefit nor synergistic effect in retarding lipid oxidation was shown by caffeic acid. MPC not only retarded lipid oxidation but also moderated texture hardening, cooking loss, and moistness during frozen storage. No improvement by caffeic acid alone and no significant differences in sensory firmness and moistness between MPC-added mince with and without caffeic acid indicate that caffeic acid did not play any role in texture and moisture control. This study suggests that lipid oxidation and texture of frozen sardine mince can be better controlled by using MPC alone.     

Convective Drying Kinetics and Physical Properties of Silver Carp (Hypophthalmichthys molitrix) Fillets

The aim of this work was to investigate drying kinetics of silver carp fillets at the temperatures of 40, 50, 60, and 70°C for two air velocities (0.5 and 1.5 m/s) and to evaluate the effect of drying temperature on the physical properties of the products. From regression analysis of the experimental data, a Two-term model was found to adequately predict the drying process at all conditions tested. Effective moisture diffusivities (D_eff) ranged between 2.47?×?10^?10 m²/s and 5.98?×?10^?10m²/s and increased with temperature and air velocity. Rehydration ratio, hardness, and springiness were significantly affected by drying temperature. Color parameters, except b*, showed no dependence on temperature.