辐照对冷却猪、鸡肉中细菌ATP发光强度的影响

采用ATP发光法检测辐照对冷却猪、鸡肉ATP发光强度的影响,并对其他试验因素是否对样品ATP发光强度产生影响进行了分析。结果表明:ATP标准品的浓度与发光强度呈显著的正相关,ATP标准品发光强度与辐照剂量表现为显著的负相关;辐照冷却肉的细菌ATP发光强度随辐照剂量的变化趋势呈现为倒"S"形特征,其中6.0kGy辐照时发光强度最大,4.0、8.0kGy剂量辐照时强度最小;无菌水、灭菌样品未对ATP发光强度造成干扰,而未辐照大肠杆菌浓度与ATP发光强度之间呈显著线性正相关,相关系数达到0.9437。     

Preliminary Trial: Motility Comparisons of a Unique Freezing Technology (UFT) to Liquid Nitrogen Mist Methodology for Cryopreservation of Porcine Spermatozoa

The motility outcomes of boar semen frozen with newly developed freezing techniques using a new unique freezing technology (UFT) compared with traditional liquid nitrogen methodology were investigated with the intent of improving current fertility outcomes using semen. The UFT is an electronically controlled cooling chamber that houses an organic fluid bath that can be maintained at temperatures below 0 degrees C without solidifying to freeze samples. Four ejaculates from four different boars were collected for this trial. Samples were handled consistently during the pre- and post-freeze processing. From each ejaculate, samples were separated into eight cryopreservation treatment groups, six UFT variations and two control liquid nitrogen groups, immediately before freezing, in replicates of two. After the initial cryopreservation was complete, all samples were stored in liquid nitrogen for at least 48 h. Post-thaw motilities and original motility return percentages were assessed on a random, individual-sample basis. After the initial evaluations, samples from two boars were recollected and frozen using the UFT for breeding purposes. Four sows were bred with the UFT frozen semen to confirm fertility capability. When assessing the individual UFT techniques, all of six UFT techniques had improved post-thaw motilities. However, treatments F (micro = 29%, return micro = 37%) and J (micro = 27%, return micro = 34%) showed the highest statistical improvement for post-thaw (p < 0.05) and original motility percent returns (p < 0.05) when compared with either the control cryo-tube (micro = 15%, return micro = 19%) or straw groups (micro = 12%, return micro = 16%). The UFT semen had a 50% conception rate, with an average of seven piglets from the sows that farrowed. Our preliminary data suggest a higher motility return with a slower pre-freeze phase below the freezing point before the acceleration to liquid nitrogen temperatures. The preliminary data suggest that the UFT could be utilized as a potential cryopreservation option for boar semen.     

Number of Follicular Waves and Their Effect on Pregnancy Rate in the Cow

In the study, the relationship of follicular growth waves, oestradiol and pregnancy rates were investigated during oestrus cycle in cows. A total of 22, Brown Swiss cows (3-5 years old) were used for the study. The ovaries of animals were examined from sixth day of cycle to next oestrus by ultrasound. The follicles that were present in the ovarium were recorded. Follicular growth was observed every day by means of ultrasound examination. The blood samples were taken for analysis of oestradiol simultaneously with ultrasound examinations. The oestrus animals were inseminated. Each animal that inseminated was examined by ultrasound on day 28 after insemination for pregnancy diagnosis. Two follicular growth waves were observed in nine of 22 (40.9%), three waves in 13 of 22 (59.1%) animals. The oestradiol was found in the same concentration but in different release patterns between two and three waves animals. Pregnancy rate in cows with three and two follicular waves did not differ. In conclusion, emergence of three waves of follicular growth was higher in Brown Swiss cows, the analysis of oestradiol could be used for determination of the wave numbers and the animals with different waves may have had the same pregnancy rates.     

High expression of Axl promotes clinical progression of nasopharyngeal carcinoma

AIM: To explore the expression and significance of receptor tyrosine kinase anexelekto (Axl) in nasopharyngeal carcinoma (NPC). METHODS: Immunohistochemistry was used to detect the Axl protein expression of 78 patients with NPC and 32 patients with nasopharyngeal chronic inflammation (NPI). The correlations between the Axl protein levels and the clinical parameters of NPC patients were analyzed. NPC cells were cultured in vitro, and the expression of Axl in well differentiated CNE1 cells, poorly-differentiated CNE2Z cells and undifferentiated C666-1 cells was detected by immunofluorescence staining. After treatment of the CNE1and C666-1 cells with Axl specific inhibitor TP-0903, CCK-8 assay was used to detect cell viability, flow cytometry was adopted to analyze the cell cycle distribution, qPCR was used to examine the mRNA levels of Axl and proliferating cell nuclear antigen (PCNA), and Western blot was used to examine the protein expression of Axl and p-Axl. RESULTS: Axl protein was localized in the cell membrane and cytoplasm. The rate of high expression of Axl in NPC was significantly higher than that in NPI (P<0.01). High Axl expression showed no correlations with NPC patients' age, gender and M stage, while positively correlated with the clinical stage, T stage and N stage (P<0.05). Axl protein showed a low level in the CNE1 cells, but showed a high level in CNE2Z and C666-1 cells. TP-0903 inhibited cell viability in concentration and time dependent manners. TP-0903 at 2 nmol/L showed significant inhibitory effects, as evidenced by arresting the cell cycle at G₀ phase and reducing Axl activity and PCNA expression. CONCLUSION: High expression of Axl promotes the clinical progress of NPC.TP-0903 significantly inhibits the viability of NPC cells, suggesting that Axl may be a valuable target in the NPC treatment.     

四种野生植物对天津盐碱地土壤改良效果的研究

选择天津市蓟县、西青和大港的荒地土壤和耐盐碱的4种野生植物(猪毛菜、草木樨、艾蒿和补血草)进行盆栽试验.植株生长5个月后,测定土壤的各项理化指标.结果显示:4种植物均大大降低土壤总盐量,猪毛菜可以不同程度地降低土壤中CO23-、SO24-和有效磷;补血草对降低土壤SO24-和水溶性钙较有效;草木樨和艾篙可以明显增加土壤有效氮含量.综合分析表明,这4种野生耐盐植物对改良盐碱地土壤效果明显.     

基于地形梯度的冀西北山地丘陵区土地利用格局变化分析——以河北省怀来县为例

为研究山地丘陵地区土地利用格局在地形差异上的演变规律,明确自然和人文因素在土地利用变化中的作用,基于RS和ArcGIS空间分析技术,利用地形位指数和分布指数,研究了河北省怀来县1993—2013年土地利用变化在地形差异上的时空分异特征。结果表明:六种土地利用类型空间分布及其变化均受到地形因子的影响和制约。水域的优势位主要分布在高程为300~500m、坡度0°~6°以及地形位级别为二级的区域;建设用地和耕地多分布于高程为500~700m、坡度0°~6°以及地形位级别为一级的区域;园地的地形适应性强于耕地,其分布的区域相对于耕地更加广泛,林地和未利用地则主要分布于高程900 m以上、坡度6°以上的区域,林地在地形位较高的级别更有优势。该文为今后怀来县土地资源的合理利用和科学规划提供依据与指导。     

鸡公山自然保护区森林生态系统服务功能及其价值初步研究

从生态系统服务功能的概念入手,根据调查和研究,采用替代工程、市场价值等方法,从2个方面评价了鸡公山自然保护区森林生态系统服务功能的价值.结果表明,面积3000hm2的鸡公山自然保护区森林生态系统的生态服务功能价值70548.6万元·a-1,其中涵养水源价值8593.9万元·a-1,净化水质价值1265.3万元·a-1,保持土壤价值57754.1万元·a-1,固碳制氧价值2114.2万元·a-1,净化环境价值(吸收SO2量)26.1万元·a-1,游憩价值550万元·a-1,林产品价值245万元·a-1.     

鸡公山自然保护区森林植被生物量及活碳蓄积量研究

运用鸡公山科学考察资料及1999年森林资源清查资料,采用森林材积源生物量推算方法研究了鸡公山森林植被生物量及其活碳蓄积量。结果表明:鸡公山森林植被生物量总值为309 202t,平均森林植被生物量为111.7t／hm2,高于全国平均水平(77.4t／hm2);鸡公山森林植被的总活碳蓄积量为154 601t,平均活碳密度为56MgC／hm2,高于中国森林植被活碳密度的平均水平(38.7 MgC／hm2),但低于全球平均碳密度(86MgC／hm2)。不同林型活碳蓄积密度分析结果表明,马尾松、杉木和栎类林木的活碳蓄积密度分别为30MgC／hm2,39 MgC／hm2和70MgC／hm2,均高于全国同类型森林植物的活碳蓄积密度的平均值,而次生阔叶混交林的碳蓄积密度略低于全国平均水平。鸡公山自然保护区67％的森林为中龄林,27％的森林为幼龄林,在增加碳蓄积方面还有巨大的潜力。     

不同作物种植模式对新垦农田土壤微生物群落功能多样性的影响

利用Biolog-ECO技术对新垦农田不同作物种植模式下土壤微生物群落功能多样性进行了研究。结果表明:不同作物种植模式对新垦农田土壤微生物群落功能多样性均有很大影响。与6年连作小麦相比较,头3年连种大蒜再轮作小麦的土壤微生物对全部碳源的利用能力最强,生理代谢活性最高,在0~144h内其平均颜色变化率(AWCD)变化最显著,土壤微生物群落优势度、多样性指数及均匀度也相对较高,说明该种作物种植模式对土壤微生物群落结构和功能多样性影响最大,可有效改善土壤贫瘠状况。