Effect of Thermal Microbial Inactivation and Washing on Quality Properties of Fish Sausage During Cold Storage (4°C)

The effect of microbial inactivation and washing process on physicochemical and sensory quality of pasteurized fish sausage during cold storage (4°C) was evaluated. Mince was obtained after the grinding; washed mince (WM) was obtained by single washing of mince; and surimi was obtained after three washing and dewatering cycles. Texture profile analysis results demonstrated that textural characteristics of pasteurized fish sausages remain stable during storage period (p > 0.05). Color analysis showed that Hunter L* had an increasing trend, and a* and b* had a decreasing trend over time (p < 0.05). Thus, it is possible to inactivate all microorganisms in pasteurized fish sausage without any undesirable effect on physicochemical and sensory quality.     

蝇蛆抗菌肽的诱导及其抗菌性能研究

为了探究灭活沙门氏菌对蝇蛆抗菌肽的诱导效果,试验用灭活沙门氏菌和沙门氏菌培养蝇蛆,粗提蝇蛆抗菌肽,分时间点测定其浓度及抗菌性能,同时对蝇蛆体内细菌含量进行计数。结果显示,诱导组抗菌肽浓度均高于未诱导组(P<0.05),且在24 h时浓度最高;诱导组对沙门氏菌的抑菌圈直径显著大于未诱导组(P<0.05),显著小于抗生素组(P<0.05),最低抑菌浓度(MIC)值为0.5 mg/mL;蝇蛆体内细菌含量为1.6×10⁵ CFU/g,低于国家规定标准饲料中细菌总数最低值2×10⁶ CFU/g。提示,用灭活沙门氏菌诱导蝇蛆能提高抗菌肽的表达量,且具有较强的抗菌性能及安全性。     

Effect of germination on vomitoxin level in grain.

The present investigation clarified the effect of enzymes or other substances formed during the germination process on the vomitoxin level of contaminated oats. The studies found that oats containing vomitoxin germinated very poorly; the decrease in toxins was also slight. The amount of pure vomitoxin added to toxin-free grain decreased (barley 53%, oats 40%, wheat 20%) during germination (5 d). In homogenized mixture of germinated grain (2.4 and 7 d) and toxic grain no decrease in toxin amount occurred during a 1-7 day period. In contrast, when germinating toxin free grains and toxic oats in a grain mixture the toxin level decreased at first, but later rose considerably. On the basis of these results, the utilization of germination processes for the improvement of grain containing vomitoxin is of questionable value.     

哺乳动物早期胚胎的剂量补偿作用及其对发育的影响

剂量补偿是使X连锁基因的表达水平在两性间达到平衡的过程。哺乳动物是通过随机失活雌性的一条X染色体实现剂量补偿。X染色体失活开始于X染色体失活中心(XIC),然后传播到整条染色体。Xist基因定位于XIC中,参与X染色体失活的启动。本文主要通过分析雄核生殖胚胎、雌核生殖胚胎和正常胚胎发育中X连锁基因表达,概括了X染色体失活(XCI)在哺乳动物早期胚胎发育中作用,综述了哺乳动物早期胚胎的剂量补偿作用及其对发育的影响。     

Optimization of Inactivation Conditions of High Hydrostatic Pressure Using Response Surface Methodology

Response surface methodology(RSM)was employed in the present work and a second order quadratic equation for high hydrostatic pressure(HHP)inactivation was built.The adequacy of the model equation for predicting the optimum response values was verified effectively by the validation data.Effects of temperature,pressure,and pressure holding time on HHP inactivation of Escherichia coli ATCC 8739 were explored.By analyzing the response surface plots and their corresponding contour plots as well as solving the quadratic equation,the optimum process parameters for inactivation E.coli of six log cycles were obtained as:temperature 32.2℃,pressure 346.4 MPa,and pressure holding time 12.6 min.     

A review of equine mucocutaneous squamous cell carcinoma

Squamous cell carcinoma (SCC) accounts for approximately 20% of all equine mucocutaneous (MC) tumours and continues to present a therapeutic challenge to practitioners. Most MC‐SCC are locally invasive and slow to metastasise, but metastasis to local lymph nodes is not uncommon. The most common location for MC‐SCC is the periorbital region, with the eyelid most commonly affected. Although only 13% of MC‐SCC involves the external genitalia, MC‐SCC is the most common neoplasm of male genitalia. Equine caballus papillomavirus‐2 has recently been linked to MC‐SCC and may prove to be necessary for tumour development. Risk factors may include chronic exposure to ultraviolet light and chronic skin irritation. Horses developing genital MC‐SCC tend to be older compared to those with periorbital MC‐SCC. Histopathology is required for definitive diagnosis of MC‐SCC, although horse phenotype and lesion location may suggest MC‐SCC. Several treatment modalities have been successful in eliminating or managing MC‐SCC, with surgical excision and intratumoural chemotherapy yielding the best results. Other treatment options including cryotherapy, hyperthermia, radiotherapy and photodynamic therapy are often used as adjunctive therapies. Early recognition of tumours and prompt intervention are associated with a positive outcome.     

不同失活预处液处理对切花月季保鲜及扦插效果的影响初探

研究失活预处液处理对月季品种黑魔术、影星切花瓶插保鲜及扦插效果的影响,结果表明：不同预处液处理对花枝吸水度、瓶插寿命、花朵开放直径及枝条扦插萌发率、生根率有显著影响.其中,未进行失活处理的预处液切花瓶插保鲜效果较好,瓶插寿命长,花枝吸水能力强.枝条扦插后萌发率高,生根好.进行失活处理的预处液,随失活成分浓度升高,切花瓶插效果明显下降,枝条扦插后坏死率高,失活效果明显.     

基于病毒mRNA监测的传染性脾肾坏死病毒灭活快速检验方法建立及其应用

为建立传染性脾肾坏死病毒(ISKNV)灭活快速检验方法,从ISKNV感染CPB细胞系转录谱筛选并经q RT-PCR验证表达量最高的病毒ORF099基因作为快速检测靶基因。以质粒p MDORF099为标准品,采用q PCR方法绘制了CT值与质粒拷贝数的标准曲线,其线性方程为CT=–3.42lgx+39.455,最低检测限为3拷贝/μL,结果显示组间和组内变异系数均小于2%,表明该方法具有较高的灵敏度和较好的重复性。将ISKNV病毒悬液10倍稀释成100~103拷贝/m L,分别取1 m L病毒稀释液接种CPB细胞,在第7、9和11天提取细胞总RNA,经基因组DNA去除试剂盒去除残留DNA后采用qRT-PCR方法检测ORF099基因转录本,结果显示在第7天即可从接种1个拷贝病毒的细胞中检测出ISKNV ORF099转录本。将3个浓度梯度(0.05%、0.1%、0.2%)的甲醛灭活ISKNV制备的模拟样品以及实验室制备的3批次ISKNV细胞灭活疫苗样品接种CPB细胞9 d,采用上述快速检验方法进行检测。0.05%、0.1%甲醛灭活模拟样品可检测到ISKNV ORF099基因转录本,其他样品均未检测到。而细胞盲传实验显示,0.1%终浓度甲醛灭活ISKNV接种细胞盲传3代未出现CPE,鱼体安全实验显示接种鱼体后无临床发病症状和实验鱼死亡,表明本研究建立的病毒灭活快速检验方法比细胞盲传法和鱼体安全实验具有更高的灵敏度,与传统检测方法相比具有灵敏度高、耗时短、检测效率高等优点,对提高ISKNV灭活疫苗生产效率具有重要意义。     

嘧肽霉素对烟草花叶病毒抑制作用研究

嘧肽霉素和烟草花叶病毒(TMV)等体积混合后接种,对心叶烟的枯斑抑制率为96.5%,对系统寄主NC89的防效为84.9%。在接种病毒前24 h喷施药剂,枯斑抑制率和对系统寄主的防效分别为75.4%和69.5%。接种病毒后24 h喷药试验表明,药剂能在一定程度上抑制进入植株体内病毒的增殖。药剂与病毒混合处理后电镜观察,病毒粒子有断裂现象,混合时间越长,破坏作用越强。嘧肽霉素对TMV具有较强的体外钝化作用,且是不可逆的。     

Aging of colloidal contaminants and pathogens in the soil environment: Implications for nanoplastic and COVID-19 risk mitigation

Colloidal contaminants and pathogens are widely distributed in soil, whose tiny sizes and distinct surface properties render unique environmental behaviours. Because of aging, colloids can undergo dramatic changes in their physicochemical properties once in the soil environment, thus leading to diverse or even unpredictable environmental behaviour and fate. Herein, we provide a state-of-art review of colloid aging mechanisms and characteristics and implications for risk mitigation. First, we review aging-induced formation of colloidal contaminants and aging-associated changes. We place a special focus on emerging nanoplastic (NP) contaminants and associated physical, chemical, and biological aging processes in soil environments. Second, we assess aging and survival features of colloidal pathogens, especially viruses. Viruses in soils may survive from several days to months, or even several years in groundwater, depending on their rates of inactivation and the reversibility of attachment. Furthermore, we identify implications for risk mitigation based on aging mechanisms. Hotspots of (photo)chemical aging of NPs, including plastic gauzes at construction sites and randomly discarded plastic waste in rural areas, are identified as area requiring greater research attention. For COVID-19, we suggest taking greater care in regions where viruses are persist for long periods, such as cold climate regions. Soil amendment with quicklime (CaO) may act as an effective means for pathogen disinfection. Future risk mitigation of colloidal contaminants and pathogens relies on a better understanding of aging mechanisms and more sophisticated models accurately depicting processes in real soil environments.