Genetic parameters of meat quality traits in two pig breeds measured by rapid methods

To study genetic variation in meat quality traits measured by rapid methods, data were recorded between 2005 and 2008 on samples of M. longissimus dorsi (LD) in Landrace (n = 3838) and Duroc (n = 2250) pigs included in the Norwegian pig breeding scheme. In addition, ultimate pH levels in the glycolytic LD (loin muscle) and M. gluteus medius (GM, ham muscle), and in the oxidative m. gluteus profundus (GP, ham muscle) were recorded as an extended data set (n = 16 732 and n = 7456 for Landrace and Duroc, respectively) from 1998 to 2008. Data were analysed with a multi-trait animal model using AI-REML methodology. Meat from Duroc had considerably more intramuscular fat (IMF), less moisture and protein, appeared darker with higher colour intensity and had lower drip loss than meat from Landrace. The heritability estimates (s.e. 0.01 to 0.07) for pH in LD (0.19 and 0.27 for Landrace and Duroc, respectively), GM (0.12 and 0.22) and GP (0.19 and 0.38), drip loss (0.23 and 0.33), colour values: L* (lightness) (0.41 and 0.28), a* (redness) (0.46 and 0.43), b* (yellowness) (0.31 and 0.33), IMF (0.50 and 0.62), muscle moisture (0.31 and 0.50) and muscle protein content (0.40 and 0.54) in LD all demonstrated moderate-to-high genetic variation for these traits in both breeds. Near infrared spectroscopy and EZ-DripLoss are modern technologies used in this study for the determination of chemical components and drip loss in meat. These methods gave higher heritabilities than more traditional methods used to measure these traits. The estimated genetic correlations between moisture and IMF in Duroc, and pH and drip loss in Duroc were both -0.89. Interesting differences between the two breeds in numerical value of some genetic correlations were observed, probably reflecting the differences in physiology and selection history between Landrace and Duroc. The estimated genetic correlation between drip loss and pH was much stronger in Duroc than in Landrace (-0.89 and -0.63, respectively). This might be due to the high pH in Duroc, whereas Landrace had a lower pH closer to the iso-electric point for muscle proteins. The positive genetic correlation between the L* value in meat and IMF in Duroc (0.50) was an effect of differences in visible marbling, rather than meat colour. For Landrace, this correlation was negative (-0.20). IMF content showed favourable genetic correlations to drip loss (-0.36 and -0.35 for Landrace and Duroc, respectively).     

叶绿素计SPAD-502在林业上应用

叶绿素是植物光合作用的色素,传统方法测定叶绿素一般采用分光光度法.本研究采用便携式叶绿素计SPAD-502测定落叶松人工林下4个主要阔叶树种绿色度（SPAD值）的季节变化,并与分光光度法测定的叶绿素含量进行相关性分析.结果表明,SPAD值与叶绿素含量具有显著的相关性,SPAD值能较好地反映树木叶绿素含量的变化.因此,使用叶绿素计测定树木的叶绿素含量是完全可行的,在一定条件下可代替叶绿素含量的直接测定.由于叶绿素计SPAD-502携带方便、测定简便、迅速,且不损坏叶片,应在林业研究中积极推广使用.     

数字式磁控脊髓夹损仪

在原磁控机械夹断装置的基础上,研制出一种新型的、定量的数字式磁控脊髓夹损仪。该仪器是根据电磁理论和力学平衡原理设计的,由定时器、电流调节器和电流表、控制电路及电磁夹具所组成。电磁夹具左、右两臂间的距离、其单或双臂作用力,运动方向和持续时间均可根据实验要求预先设置和调整。流经电磁夹具单臂或双臂的电流可在数字显示屏上显示并保持。本仪器操作简便可靠,还可直读,适用于复制不同种系动物的不同类型和程度的脊髓损伤。     

动物室氨浓度两种检测方法的对比

目的寻找方便、快捷、准确的实验动物环境中氨浓度检测方法。方法通过对《实验动物环境及设施》（GB14925-2001）中规定的纳氏试剂比色法和近年国内引进的Ammonia meter法两种检测室内的氨气浓度的方法比较研究。结果纳氏试剂比色法和Ammonia meter法检测结果存在差异显著性。结论在现阶段Ammonia meter法代替传统的纳氏试剂比色法的条件尚不成熟。同时,对实验采用方法进行说明。建议现行标准的吸收液浓度由0.5 mol/L修改为0.05 mol/L,吸收波长由500 nm修改为420 nm。     

An assessment of morphometric indices,blood chemistry variables and an energy meter as indicators of the whole body lipid content in Micropterus dolomieu,Sander vitreus and Ictalurus punctatus

The effectiveness of several non‐lethal techniques as indicators of total lipid content in smallmouth bass Micropterus dolomieu, walleye Sander vitreus and channel catfish Ictalurus punctatus was investigated. The techniques included (1) the Fulton and relative condition factors, (2) relative mass, (3) plasma indicators of nutritional status (alkaline phosphatase, calcium, cholesterol, protein, triglycerides and glucose) and (4) readings from a hand‐held, microwave energy meter. Although simple linear regression analysis showed that lipid content was significantly correlated with several predictor variables in each species, the r² values for the relations ranged from 0·17 to 0·50 and no single approach was consistent for all species. Only one model, between energy‐meter readings and lipid content in I. punctatus, had an r² value (0·83) high enough to justify using it as a predictive tool. Results indicate that no single variable was an accurate and reliable indicator of whole body lipid content in these fishes, except the energy meter for I. punctatus.     

Occupational exposure in a PET/CT facility using two different automatic infusion systems

PurposeThe aim of this study was to measure the occupational exposure using active personal dosimeters (APD) in the PET/CT department at different stages of the operation chain i.e. radiopharmaceutical arrival, activity preparation, dispensing, injection, patient positioning, discharge and compare the radiation exposure doses received using two automatic injection/infusion systems. This paper also reflects optimization processes that were performed to reduce occupational exposure.MethodsMeasured APD data were analysed for medical physicists, radiology technologists and administrative staff from 2014 till 2018. For dispensing and injecting ¹⁸F-FDG, the automatic infusion/injection system IRIDE (Comecer, Italy) or the automatic fractionator ALTHEA (Comecer, Italy) with wireless injection system WIS (Comecer, Italy) were used. Radiation exposure optimization methods were applied during the data collection period (installation of the transport port, patient management, APD alarm threshold and etc.).ResultsRadiology technologists who perform injection procedures, regardless of the automatic infusion system, received the highest radiation exposure dose. The average doses to the radiology technologists per one study were 1.72 ± 0.33 μSv and 1.16 ± 0.11 μSv with ALTHEA/WIS and IRIDE system, respectively. The average dose for accompanying the patient to the PET/CT scanner and scan procedure was 0.52 ± 0.07 μSv. For the medical physicists, the average dose was 0.29 ± 0.09 µSv. The measured dose for administrative staff was 0.30 ± 0.15 μSv.ConclusionsOccupational exposure can be effectively optimized by different means including staff monitoring with APD, implementation of radiation safety culture and the usage of automatic infusion systems.     

Study on Omentin-1 and miR-502-3p in osteoporotic fracture

Objectives:To explore the expression and correlation of Omentin-1 and miR-502-3p in serum of patients with osteoporotic fracture (OPF).Methods:Sixty OPF patients diagnosed and treated in our hospital from June 2018 to December 2019 were included in group A. Fifty-six osteoporosis patients without fractures were included in group B. Omentin-1 and miR-502-3p levels were detected by enzyme-linked immunosorbent assay (ELISA) and real-time quantitative PCR (qRT-PCR). Their predictive value for diagnostic efficiency was assessed by ROC curve. Spearman’s rank correlation test was used for correlation analysis. The risk factors related to the prognosis of OPF were analyzed by Logistic univariate and multivariate analysis.Results:The expression of Omentin-1 and miR-502-3p in group A was markedly lower than in group B (P<0.001). Spearman correlation analysis showed that in OPF, there was a negative correlation between serum Omentin-1 and TNF-α (r=0.8579, P<0.001), a negative correlation between serum miR-502-3p and TNF-α (r= 0.8653, P<0.001), and a positive correlation between serum Omentin-1 and miR-502-3p (r= 0.8764, P<0.001).Conclusions:Omentin-1 and miR-502-3p were down-regulated in serum of patients with OPF, both of which could be used as potential biomarkers for the diagnosis and disease evaluation of OPF.     

The Multicenter Aerobic Iron Respiratory Chain of Acidithiobacillus ferrooxidans Functions as an Ensemble with a Single Macroscopic Rate Constant

Electron transfer reactions among three prominent colored proteins in intact cells of Acidithiobacillus ferrooxidans were monitored using an integrating cavity absorption meter that permitted the acquisition of accurate absorbance data in suspensions of cells that scattered light. The concentrations of proteins in the periplasmic space were estimated to be 350 and 25 mg/ml for rusticyanin and cytochrome c, respectively; cytochrome a was present as one molecule for every 91 nm² in the cytoplasmic membrane. All three proteins were rapidly reduced to the same relative extent when suspensions of live bacteria were mixed with different concentrations of ferrous ions at pH 1.5. The subsequent molecular oxygen-dependent oxidation of the multicenter respiratory chain occurred with a single macroscopic rate constant, regardless of the proteins'' in vitro redox potentials or their putative positions in the aerobic iron respiratory chain. The crowded electron transport proteins in the periplasm of the organism constituted an electron conductive medium where the network of protein interactions functioned in a concerted fashion as a single ensemble with a standard reduction potential of 650 mV. The appearance of product ferric ions was correlated with the reduction levels of the periplasmic electron transfer proteins; the limiting first-order catalytic rate constant for aerobic respiration on iron was 7,400 s⁻¹. The ability to conduct direct spectrophotometric studies under noninvasive physiological conditions represents a new and powerful approach to examine the extent and rates of biological events in situ without disrupting the complexity of the live cellular environment.     

不同类型益生菌制剂在胃肠道中耐受程度的对比

目的 对市场销售的几种不同类型益生菌制剂进行胃、肠液耐受程度比较,评价各益生菌制剂活菌数量,为临床选择益生菌制剂提供参考。 方法 选择7种菌粉及某颗粒益生菌、国产某晶球、日本产某晶球、某胶囊益生菌、圣邦步步佳肠释益生菌共12种口服益生菌产品,在崩解时限仪中加入人工胃液进行崩解试验,在0.0 h、0.5 h、1.0 h、1.5 h和2.0 h时吸取上述样品并进行浓度梯度稀释,并在MRS固体培养基上培养后进行活菌计数。在上述5个时间点吸取部分益生菌-胃液混合物(针对益生菌粉末)或取出益生菌产品(针对晶球、肠溶胶囊、肠释益生菌)换人工肠液再进行40 min崩解,在MRS固体培养基上培养后进行活菌计数。 结果 粉末状益生菌制剂对人工胃液的耐受能力普遍较差。某颗粒益生菌、国产某晶球、日本产某晶球、某胶囊益生菌、圣邦步步佳肠释益生菌在人工胃液中不崩解。圣邦步步佳肠释益生菌在人工肠液中40 min完全崩解且活菌数峰值较高。 结论 圣邦步步佳肠释益生菌对人工胃、肠液耐受能力较强,且活菌数较高。     

An important role of a pyrethroid-sensing residue F1519 in the action of the N-alkylamide insecticide BTG 502 on the cockroach sodium channel

Deltamethrin, a pyrethroid insecticide, and BTG 502, an alkylamide insecticide, target voltage-gated sodium channels. Deltamethrin binds to a unique receptor site and causes prolonged opening of sodium channels by inhibiting deactivation and inactivation. Previous ²²Na⁺ influx and receptor binding assays using mouse brain synaptoneurosomes showed that BTG 502 antagonized the binding and action of batrachotoxin (BTX), a site 2 sodium channel neurotoxin. However, the effect of BTG 502 has not been examined directly on sodium channels expressed in Xenopus oocytes. In this study, we examined the effect of BTG 502 on wild-type and mutant cockroach sodium channels expressed in Xenopus oocytes. Toxin competition experiments confirmed that BTG 502 antagonizes the action of BTX and possibly shares a common receptor site with BTX. However, unlike BTX which causes persistent activation of sodium channels, BTG 502 reduces the amplitude of peak sodium current. A previous study showed that BTG 502 was more toxic to pyrethroid-resistant house flies possessing a super-kdr (knockdown resistance) mechanism than to pyrethroid-susceptible house flies. However, we found that the cockroach sodium channels carrying the equivalent super-kdr mutations (M918T and L1014F) were not more sensitive to BTG 502 than the wild-type channel. Instead, a kdr mutation, F1519I, which reduces pyrethroid binding, abolished the action of BTG 502. These results provide evidence the actions of alkylamide and pyrethroid insecticides require a common sodium channel residue.