Subjects: Digital Publishing >> New Media submitted time 2023-10-08 Cooperative journals: 《中国传媒科技》
Abstract：近年来,社会经济的飞速发展以及科学技术的不断进步,推动媒体行业进入全新发展阶段,促进媒传播体由传统单项方式转变为多项方式,不仅提高了信息传播范围和传播速度,还强化了用户间的沟通交流能力。在这一时代背景下,媒体融合成为当前社会最新发展主流。地方电视台作为传统媒体中的重要组成部分,在新媒体环境中受到巨大冲击。为了提高核心竞争力,扩大受众范围,地方电视台需要充分发挥自身优势,并强化与新媒体的融合交流,通过打造全新的媒体互动平台,开辟出适合自身发展的道理,从而改善传统媒体发展中存在的不足之处。因此,本文结合新媒体时代传播特征进行分析,并深入地方电视台在新媒体环境中面临的挑战,针对性提出媒体融合发展路径,希望能够为专业人士提供参考借鉴,为推动地方电视台稳定发展奠定基础。
Subjects: Library Science，Information Science >> Library Science submitted time 2023-08-27 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/significance] Patent similarity detection assists the formulation of the national innovation strategy planning macroscopically, finds hotspots in China and all over the world, and deals with patent rogues in other countries. Microscopically, patent similarity detection provides support for patent inventors, patent examiners and patentees.[Method/process] A new method was proposed based on deep learning of Doc2Vec model, with patent corpus based on no data clearance of domain knowledge. Then typical patents were randomly selected to carry on similarity detection by this new method, and the results with traditional similarity detection models were compared.[Result/conclusion] According to experimental results, the new deep learning of Doc2Vec method and TFIDF model has similary results which both of the model's patent corpus all based on no data clearance of domain knowledge.The new method requires less professional skill in specific domain knowledge, and didn't require the process of data clearance. It can givesa new intelligent support tool for patent infringement and patent investigation, reduce the research threshold and workload, and improve service efficiency.
Subjects: Library Science，Information Science >> Library Science submitted time 2023-07-26 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/significance] Although there have been efforts of scholars to answer the question, what’s determinants of patent citation formation are not solved satisfactorily. Scholars find formation of patent citation is influenced by the structure characteristics of patent citation network. However, the current framework of statistical inference methods based on logistical regression is failing to incorporate the above factors, so an innovative method need to be introduced. [Method/process] From a tie formation perspective, patent citation formation represents three broad category of tie formation processes: attribute-based processes, self-organizing network processes and covariates processes. Furthermore, based on these processes, the paper establishes a mapping relationship between those processes with particular types of configurations. Finally, a framework is proposed for understanding the complexity of patent citation formation. [Result/conclusion] The paper introduces a framework for understanding patent citation formation, which lays the groundwork for statistical network modeling in the future. In addition, broadly network configuration selection from the framework offers significant opportunities to extend existing bibliometrics and open new pathways in complexity of scientific network analysis.
Subjects: Medicine, Pharmacy >> Preventive Medicine and Hygienics submitted time 2023-07-06 Cooperative journals: 《中国全科医学》
Abstract： Background Currently，there are many studies on family doctor contracting services from the perspective of residents，but few scholars have conducted studies on the current situation of family doctor team contracting based on the perspective of general practitioners. Objective To understand the current situation of family doctor contracting services in primary health care institutions in Guangdong Province，and explore the factors affecting the contracted number from the perspective of the supplier（GPs）. Methods From July 5—31，2021，GPs in primary health care institutions in Guangdong Province were selected as the study subjects by using a multi-stage stratified cluster sampling method to conduct the survey with a self-designed questionnaire. The contracted number was compared by different GPs and their family doctor team characteristics. A two-level Logistic regression developed by R 4.2.2 software was used to identify influencing factors of contracted number above 2000. Results A valid sample of 3 252 cases in family doctor team with contracted number more than 100 was screened，and the median contracted number was 1 400（2 499）in 2020. The differences were statistically significant when comparing the contracted number by gender，age，education level，position，employment form，working years，working unit，working area，training acceptance，and annual income，number of team members，population size under jurisdiction，willingness of specialists from medical community to join the team，inpatient bed resources and guidance from superior departments（P<0.05）. Zero model fitting showed that contracted number was clustered at the regional level（P<0.05）. Two-level Logistic regression model showed that，with master's degree as the reference，the contracted number of the team including GPs with college〔OR（95%CI）=2.79（1.84，3.74）〕and secondary/high school〔OR（95%CI）=2.83（1.80，3.86）〕degrees were more likely to be above 2 000；taking no position as reference，the contracted number of the team including unit leaders〔OR（95%CI）=0.66（0.33，0.99）〕were more likely to be above 2 000；taking temporary staff as reference，the contracted number of the team including formal staff〔OR（95%CI）=2.02（1.53，2.51）〕were more likely to be above 2 000；taking the team with size of 3 or less people as reference，the contracted number of the teams with size of 4 to 6 people〔OR（95%CI）=1.31（1.05，1.57）〕，7-10 people〔OR（95%CI）=2.06（1.75，2.37）〕，11-19 people〔OR（95%CI）=3.67（3.31，4.03）〕and≥ 20 people〔OR（95%CI）=3.46（2.74，4.18）〕were more likely to be above 2 000；taking population size under jurisdiction at 2 000 or less as reference，the contracted number of the team with population size under jurisdiction at 2001 to 9999〔OR（95%CI）=2.37（2.12，2.62）〕，10 000 to 29 999〔OR（95%CI）=2.92（2.65，3.19）〕and more than 30 000〔OR（95%CI）=2.86（2.55，3.17）〕were more likely to be above 2 000；taking condition of having inpatient bed resources as reference，the contracted number of the teams without such resources〔OR（95%CI）=1.38（1.14，1.62）〕were more likely to be above 2 000. Conclusion The population under jurisdiction and the large number of team members create favorable conditions for contracting；family doctor teams with GPs with positions，inpatient bed resources and high education level have a good understanding of family doctor contracting service policies and control the number of contracted patients better；comparing with temporary staff，GPs team with formal staff may undertake more contracting tasks.
Subjects: Library Science，Information Science >> Information Science submitted time 2023-04-01 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/significance] Comparative documents are important for judging whether a patent can be granted or invalid. Aiming at the shortcomings of traditional information retrieval methods and rarely using machine learning methods to study the issue of comparative document retrieval, based on the introduction of comparative file information, this paper constructs a patent relevance determination model.[Method/process] Experiments were performed by using the target patents and comparative documents in the patent invalidation judgment as the data set to extract text similarity, co-occurrence vocabulary, and co-word quantity feature information. The GBDT model was used to convert the retrieval of comparative documents into classification issues that determined whether they were relevant.[Result/conclusion] The research results show that the contribution of different field data to the classification effect is different, in which the F1 of the description text reaches 59%, and the classification effect after multi-feature integration is significantly better than the result of single text similarity. Finally, this paper analyzes the experimental misclassifications and points out the next research directions.
Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-28 Cooperative journals: 《中国科学院院刊》
Abstract： none
Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-28 Cooperative journals: 《中国科学院院刊》
Abstract： The Yellow River is known as China’s Mother River, which fosters the great and profound Chinese civilization. However, the frequent flood and drought disasters have also brought serious disasters to the people who live in the Yellow River Basin. At present, significant changes have taken place in the climate and hydrological processes of the Yellow River Basin due to global warming and human activities. The warming and drying climate and increase of human water use in the Yellow River Basin have led to an increase in hydrological drought. Although the Grain for Green program has greatly improved the vegetation coverage on the Loess Plateau and effectively inhibited severe soil erosion, but also enhanced the soil desiccation and enlarged the dry soil layers in this area. These phenomena are not only the major challenges for ecological protection and high-quality development in the Yellow River Basin, but also the basic scientific issues which related to the coordinated development of climate-water-ecology-society.
Subjects: Psychology >> Social Psychology submitted time 2023-03-27 Cooperative journals: 《心理学报》
Abstract： Bullying victimization represents the experience of being the target of aggression by one or several peers while not being able to defend oneself. This phenomenon has high prevalence among children and youth, with approximately 32% school-aged children across the world being bullied by their class- or schoolmates. Exposure to bullying victimization puts children at risk for a variety of social-psychological maladjustment, both internalizing and externalizing. However, the likelihood of victimization leading to maladjustment might vary across contexts. Recent research found that victims were more likely to be maladjusted in relatively healthier contexts (i.e. classrooms with low overall levels of victimization) -- a phenomenon that has been referred to as the "healthy context paradox (HCP)". Specifically, extant studies found that victimized children were more likely to exhibit internalizing problems in classrooms with low levels of victimization. However, little is known about whether classroom-level victimization moderates the link between bullying victimization and externalizing problems. More importantly, no empirical study has specifically examined the underlying mechanisms of HCP. According to the social information processing theory and existing studies, it is reasonable to assume that in relatively healthier contexts, victimized children are more likely to feel targeted by peers and develop a hostile attribution bias, which in turn leads to more externalizing problems. Therefore, hostile attribution bias, a tendency to attribute hostile intent to another person in ambiguous and even neutral situations, can be a potential mechanism explaining the paradoxical effect of classroom-level victimization on victim's externalizing behaviors. The present study examined whether classroom-level victimization moderated such victimization-externalizing associations, and further examined the mediating role of children’s hostile attribution bias in the associations. The sample comprised 1764 fifth- to eighth- graders (956 boys, Mage = 14.46) from 47 classes in 5 schools in Shandong, China. Bullying victimization was assessed via the Olweus Bully/Victim Questionnaire. Hostile attribution bias was measured through the Assessment of Intent Attributions for Ambiguous Provocation Situation. Externalizing problems were assessed on the Child Behavior Checklist-Youth Self-Report (CBCL-YSR). Classroom-level victimization was calculated by averaging individual bullying victimization scores for each classroom. All measures had good reliability and validity. Multi-level structural equation models were conducted to test the hypothesis. The results revealed that: (1) after controlling for sex, parental education, grade, and class size, classroom-level victimization moderated the association between bullying victimization and externalizing problems, such that the victimization-externalizing association was stronger in classrooms with a lower level of victimization compared with those in the classrooms with a higher level of victimization; and (2) low levels of classroom-level victimization strengthened victims' hostile attribution bias, which in turn was associated with externalizing problems. The present study has two major strengths. First, we extended the literature on the healthy context paradox by examining the role of classroom-level victimization in the victimization-externalizing association. In line with the hypothesis regarding the healthy context paradox, victimized children were more likely to exhibit externalizing problems in classrooms with a low level of victimization. Second, a mechanism regarding the healthy context paradox was identified, such that low classroom-level victimization had an impact on victims’ externalizing problems by increasing their hostile attribution bias. These findings highlight the importance of concentrating on specific victims and providing help for them in prevention/intervention practices. Specifically, to alleviate victims’ maladjustment, teachers and school counselors could take efforts to reduce their hostile attribution. Future studies would benefit from replicating these findings using a longitudinal design, and multiple informants to assess externalizing problems. Moreover, future studies need to test more possible explanations for the healthy context paradox.#healthy context paradox, bullying victimization, externalizing problems, classroom victimization, hostile attribution bias
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-19 Cooperative journals: 《金属学报》
Abstract： The formation of amorphous phase has been investigated in U-Co system over a wide range of compositions, namely, UxCo100-x (x=50~87.5) by mean of melt-spinning. Phase identification for the arc-melted ingots and rapidly quenched alloys, and the thermal stability of the amorphous phases thus formed have been examined by XRD and DSC, respectively. The component phases in the ingot alloys were structurally the same as those presented in U-Co phase diagram, but were associated with a certain compositional metastability. Rapid quenching experiment revealed that the ease of formation of amorphous phase occurred within the composition range of 58.5≤x≤78, and amorphous phase was most readily formed in the vicinity of U66.7Co33.3 composition. The dynamical crystallization temperatures of the amorphous phases were determined to be 534~550 K at a DSC heating rate of 20 K/min, and the highest reduced crystallization temperature (relative to the liquidus temperature) as calculated to be 0.535, and moreover, the exothermal enthalpies of crystallization were determined to be in a range of 4.8~8.5 kJ/mol. Upon room temperature electrochemical polarization in a 50×10- 6 Cl- electrolyte, these amorphous alloys exhibited corrosion potentials as high as about -50 mV, being much more positive than that of depleted uranium. In these amorphous alloys, it has also been found that the rust resistance performance appears to be parallel to the ease of amorphous phase formation.
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. submitted time 2022-11-16 Cooperative journals: 《中国全科医学》
Abstract：
Background Percutaneous coronary intervention is an effective treatment for coronary heart disease in cardiology department. In the process of coronary intervention, it faces various complex lesions, among which calcification of target vessels increases the difficulty of intervention, immediate risk of operation and the occurrence of short-term and long-term cardiovascular adverse events after operation. Early identification and evaluation of calcified lesions is of great significance to improve the success rate of surgery, reduce surgical complications, reduce cardiovascular events and improve prognosis. Objective: To explore the risk factors of calcification of target vessels in patients with coronary heart disease, and to provide evidence for early prevention, early detection and interventional therapy of coronary artery calcification.Objective To explore the risk factors of calcification of target vessels in patients with coronary heart disease, and to provide evidence for early prevention, early detection and interventional therapy of coronary artery calcification.Methods From January 2021 to December 2021, 353 patients with coronary heart disease were diagnosed by coronary angiography, of which 196 met the admission criteria. All the patients were examined by intravascular ultrasound. According to the analysis of the intravascular ultrasound imaging data of the diseased vessels, 73 cases were divided into non-calcification group (calcification index = 0) and 123 cases into calcification group, and then the calcification group was divided into low calcification index group (calcification index 0.0001-0.2166) 62 cases and high calcification index group (calcification index > 0.2166) 61 cases according to the median calcification index (M=0. 2166). Multivariate Logistic regression was used to analyze the risk factors of coronary calcification.Results There were significant differences in age, sex, prevalence of hypertension, diabetes, smoking history and thyroid disease among the three groups (P < 0.05). There were significant differences in total protein, alkaline phosphatase, glutamyltransferase, white ball ratio, triglyceride-glucose index, triglyceride, blood phosphorus and glycosylated hemoglobin among the three groups (P < 0.05). Multivariate Ordered Logistic Regression Analysis: Age (P=0. 001, OR=1. 07, 95% CI: 0.029-0.107); Alkaline phosphatase (P=0. 003, OR=1. 028, 95% CI: 0.009-0.046); Triglycerides (P=0. 015, OR=3. 174, 95% CI: 0.299-2.081); Blood phosphorus (P=0. 006, OR=13. 681, 95% CI: 0.747-4.486); Bivariate correlation (Spearman) analysis showed that age alkaline phosphatase level of triglyceride and serum phosphorus were positively correlated with coronary calcification index (P < 0.05).Conclusion Age, alkaline phosphatase, triglyceride and blood phosphorus are independent risk factors for coronary artery calcification.
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2022-06-06 Cooperative journals: 《计算机应用研究》
Abstract： In the large data environment, there are many problems in the parallel deep convolution neural network (DCNN) algorithm, such as excessive data redundancy, slow convolution layer operation and poor convergence of loss function. This paper proposed a parallel deep convolution neural network optimization algorithm based on the Im2col method. First, the algorithm proposed a parallel feature extraction strategy based on Marr-Hildreth operator to extract target features from data as input of convolution neural network, which can effectively avoid the problem of excessive data redundancy. Secondly, the algorithm designed a parallel model training strategy based on the Im2col method. The redundant convolution kernel is removed by designing the Mahalanobis distance center value, and the convolution layer operation speed is improved by combining the MapReduce and Im2col methods. Finally, the algorithm proposed an improved small-batch gradient descent strategy, which eliminates the effect of abnormal data on the batch gradient and solves the problem of poor convergence of the loss function. The experimental results show that IA-PDCNNOA algorithm performs well in deep convolution neural network calculation under large data environment and is suitable for parallel DCNN model training of large datasets.
Subjects: Mathematics >> Theoretical Computer Science submitted time 2021-07-26
Abstract： "
Peer Review Status:
Awaiting Review
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2020-07-02 Cooperative journals: 《干旱区研究》
Abstract：利用中亚地区65个气象站的逐日最高气温数据，结合ERA-Interim再分析资料以及经纬度、海拔数据，构建了随机森林插值模型，并验证了其可靠性。基于该模型补全了气象站缺失值，获得完整的站点逐日最高气温数据集TStation_f，并插值得到中亚1979—2016年空间分辨率为0.75°×0.75°的逐日最高气温格点数据集TRFIM_G。基于TRFIM_G进一步分析了中亚1979—2016年夏季极端高温指数时空变化特征。结果表明：中亚区域平均极端高温指数增速在0.22—0.30℃·(10a)-1，显著增温的区域主要分布在哈萨克斯坦的西部、土库曼斯坦大部、乌兹别克斯坦东南部等地区。基于TRFIM_G得到的夏季极端高温指数增速显著大于基于TStation_f得到的结果，这表明用站点观测数据对该地区夏季极端高温趋势的估计明显偏低。本研究得到的数据集可在一定程度上弥补使用站点观测数据片面刻画中亚地区极端高温变化的缺陷，有助于更确切地引导人们在应对极端天气气候事件时采取相应的减缓和适应措施。
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2020-04-26 Cooperative journals: 《干旱区研究》
Abstract：为了解柴达木盆地内近57 a来降水量变化与太阳黑子、北极涛动（AO）和厄尔尼诺-南方涛动(ENSO)等因素间的关系，运用线性趋势法、MannKendall检验法和小波分析法等对盆地内8个气象站的降水量进行了分析。发现近57 a来盆地内降水量年平均增加0.628 mm，夏季增加0.423 mm，夏季降水占全年总增加量的67%，年降水量存在2~3 a和1 a的显著周期。降水量与太阳黑子相对数存在近似正相关的8~12 a的主共振周期，降水量滞后1.2~1.8 a。年降水量与AO主要存在近似正相关的2~3 a和1~2 a的共振周期。年降水量与ENSO存在近似负相关的3 a和近似正相关的5~6 a的共振周期。表明盆地内降水与其天气动力因素在不同的周期尺度上存在不同的相关性。
Subjects: Biology >> Botany >> Applied botany submitted time 2019-08-26 Cooperative journals: 《广西植物》
Abstract： As a critical part of wetland system in Guizhou plateau, lake Caohai plays important roles in the maintains of ecological balance,healthy and harmonious species diversity and the regional climate regulation. In order to stabilize the wetland and sustainable development resource,it is critical important to study the characteristics of heavy metals pollution in atmospheric deposition flux and pollution characteristics. By the susceptibility and tolerance of bryophytes to heavy metals, MossBag method was used to monitor the heavy metal pollution around the lake for seven heavy metals (Cu,Pb,Zn,Cd,Cr,As and Hg )analyses,and to provide a basic data for the ecological environment protection of Caohai.The contents of seven elements such as Cu, Pb, Zn, Cd, Cr, As and Hg were detected by ICP-MS and atomic fluorescence. The sediment flux was calculated. The principal component analysis and correlation analysis are applied to study their characteristicsand origin of such pollutants,while the ecological risks of these 7 heavy metals were evaluated using geoaccumulation index method. The study results showed that the heavy metals in atmospheric deposition fluxes of Caohai Lake was a significant difference. Among which Cu and Zn deposition fluxes are far higher Pb,Cd,Cr,As and Hg, reaching 21.43 μg•m-2•d-1 and 102.82 μg•m-2•d-1 with accounting for a large total deposition fluxes radio. The correlation analysis shows that there is a positive correlation between As and Cr, Zn and Cu, indicating they are from similar or same sources,with the same chemical and environmental behaviors.However,there is no significant correlation between other metals. Applying the geoaccumulation Index method,the following conclusions are reached: all seven heavy metals were seriously polluted, of which Cd was in the extremely high pollution level. Combing the study results with the characteristics and sources of heavy metal pollution around Caohai wetland, heavy metal pollutions were considered mainly caused by many factors,including industrial structure and production and life style, and even the leftover of primitive zinc smelting industry in the vicinity.
Subjects: Biology >> Bioengineering submitted time 2019-03-05 Cooperative journals: 《中国生物工程杂志》
Abstract： Objective: A new material with ultra-large surface area named nano-forest is prepared by Micro-Electro-Mechanical System(MEMS) processing technology. Based on this material, a new microfluidic chip for point-of-care test with simple operation, rapid detection and high sensitivity is created. Methods: The fabrication of nano-forests in micro-channel on quartz substrate mainly includes: cleaning and drying of quartz substrate; spinning polyimide(PI) coating; re-spinning phenolic resin photoresist on PI coating; photolithography to expose the channel; treating the PI layer with oxygen plasma and argon plasma to synthesize nano-fiber forests structure; nano-fiber-quartz nanoforests are realized by using nano-fiber forests as nanomasks in anisotropic etching of quartz by using reactive ion etching (RIE); the micro-channel with nano-forests structure inside is achieved after removing upper nanofiber forests structure and phenolic resin photoresist coating.The height, width, density and specific surface area of nano-forest are studied and analyzed by scanning electron microscope(SEM). Optical properties are tested by ultraviolet-visible spectrophotometer. The driving force is characterized by the flow rate of PBS solution.The sensitization effect is evaluated by saturated fluorescence test through antibody and AbFluor 680 dye-labeled secondary antibody. The sample pad, bond pad, micro-channel with nano-forests structure, nitrocellulose membrane and absorbent material are assembled on PMMA substrate in sequence, which is the microfluidic chip. The chip based on the sandwich format with a polyclonal antibody and a AbFluor 680 dye-labeled secondary antibody is used to detect ricin toxin(RT). Results: The scanning electron microscope shows that the nanofiber forests structure is formed on quartz substrate after oxygen plasma and argon plasma bombardment. The single nanofiber is upright on the substrate with a diameter of about 50-100 nm, a height of 1.8 um and a density of about 20/μm2. The quartz nano-forests structure can be obtained after RIE with nano-fibre forests structure as mask and resist removal. The single structure is shaped like a cone. The diameter of the cone bottom is about 100-200 nm, the height is about 1.0 um, the density is about 10/μm2, and the surface area to bottom area is more than 5:1. Self-driven test provides information of the flow rate of PBS is to be about 5 mm/s in the micro-channel on the basis of nano-forests structure. The transmittance of the channel is 89.5%at 680 nm wavelength. It shows that the channel has good transmittance, which makes the loss of excitation light or emission light much less, and is conducive to the sensor capturing more signals. With same surface modification, the planar quartz structure has shortcomings of short lasting effect time and low saturation fluorescence intensity. To the contrary, nano-forests structure with ultra-large surface area has a good sensitization effect in the test. RT can be detected sensitively based on the significantly fluorescent intensity.The linear range of detection is from 10 pg/mL to 6250 pg/mL and the limit of detection (LOD) is lower than 10 pg/mL. Conclusion: The nano-forests structure with good optical properties reduces the requirements of sensor and also makes the choice of fluorescent dyes wider.The three-dimensional structure of the nano-forest has an ultra-large surface area, which increases the amount of antibody compared to the planar structure, and thus improves the sensitivity of detection greatly. Compared with the immunochromatographic test strip, the microfluidic chip has an advantage of high sensitivity, thus the quantitative analysis can be realized within a certain range. Most microfluidic chips require complex equipments to provide driving force, which will make them costly and bulky. Driven by the capillary force, the chip with nano-forests structure inside makes the detection simple and fast. Combined with the miniaturized detection terminal, the platform can be miniaturized, portable, and automated, achieving the goal of simple, fast and efficient analysis. These characteristics make the chip an ideal candidate for the development of rapid detection methods.
Subjects: Biology >> Zoology submitted time 2018-12-24 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究L-茶氨酸对过氧化氢（H2O2）诱导山羊瘤胃上皮细胞凋亡的保护作用。采集42日龄的湘东黑山羊的瘤胃组织进行原代细胞分离、培养、纯化。对照组采用完全培养基，Ⅰ、Ⅱ、Ⅲ、Ⅳ组分别在完全培养基中添加800 µmol/L H2O2、4 mmol/L L-茶氨酸+800 µmol/L H2O2、8 mmol/L L-茶氨酸+800 µmol/L H2O2和16 mmol/L L-茶氨酸+800 µmol/L H2O2，每组3个重复。培养12 h后，采用噻唑蓝（MTT）法检测细胞存活率，采用流式细胞术检测细胞周期，采用实时定量PCR法和蛋白质印迹（Western blot）法检测Bax和Bcl-2基因及其蛋白的表达。结果表明：L-茶氨酸能显著提高H2O2损伤的瘤胃上皮细胞存活率（P<0.05），显著增加S期细胞比例（P<0.05），显著降低Bax基因和蛋白表达量（P<0.05），显著提高Bcl-2基因和蛋白表达量（P<0.05），显著提高Bcl-2和Bax基因和蛋白表达量的比值（P<0.05）。结果提示，L-茶氨酸能通过抑制细胞凋亡来有效地保护由H2O2导致的瘤胃上皮细胞损伤；体外条件下，培养液中添加的L-茶氨酸浓度高于8 mm/L时能有效发挥抗凋亡作用。
Subjects: Biology >> Zoology submitted time 2018-12-24 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在利用单胃动物仿生消化系统（SDS-Ⅱ）研究外源淀粉酶对肉鸡玉米-豆粕型饲粮体外养分消化率和代谢能的影响，为准确评价饲用酶制剂的有效性提供依据。试验采用2×4双因素完全随机设计，参照我国《鸡饲养标准》（NY/T 33-2004）和NRC（1994）鸡营养需要配制肉鸡1~21日龄和22~42日龄玉米-豆粕型基础饲粮，并分别在2种基础饲粮中添加1 840、9 200和18 400 U/g的外源淀粉酶配制6种添加淀粉酶的饲粮，以不添加外源淀粉酶的2种基础饲粮作为对照，利用SDS-Ⅱ测定8种饲粮的体外干物质消化率（IVDMD）、体外表观粗蛋白质消化率（IVACPD）、体外标准化粗蛋白质消化率（IVSCPD）、体外淀粉消化率（IVSTD）、体外总能消化率（IVGED）和体外代谢能（IVME）。每种饲粮设5个重复，每个重复设1根消化管。结果表明：1）与对照组相比，1 840、9 200和18 400 U/g淀粉酶组饲粮胃阶段的IVDMD和IVGED均显著增加（P<0.05）；18 400 U/g淀粉酶组饲粮的IVME显著高于其他组（P<0.05）；22~42日龄饲粮的全消化道IVDMD、IVGED以及IVME均显著高于1~21日龄饲粮（P<0.05）。2）1 840和9 200 U/g淀粉酶组的全消化道IVACPD和IVSCPD均显著高于对照组（P<0.05），22~42日龄饲粮的全消化道IVACPD和IVSCPD显著高于1~21日龄饲粮（P<0.05）。3）8种饲粮的全消化道IVSTD均在99.40%以上，9 200和18 400 U/g淀粉酶组的全消化道IVSTD显著低于对照组（P<0.05），1~21日龄饲粮的全消化道IVSTD显著高于22~42日龄饲粮（P<0.05）。4）饲粮营养水平和淀粉酶添加剂量对肉鸡饲粮IVDMD、IVDGE、IVACPD、IVSCPD、IVSTD和IVME均存在交互作用（P<0.01）。在本试验条件下，外源淀粉酶的添加提高了肉鸡饲粮胃阶段的IVDMD、IVDGE，1 840和9 200 U/g外源淀粉酶提高了肉鸡饲粮的IVACPD、IVSCPD，18 400 U/g外源淀粉酶提高了肉鸡饲粮的IVME；玉米-豆粕型饲粮中淀粉几乎完全降解，外源淀粉酶对IVSTD的影响可以忽略；饲粮营养水平和外源淀粉酶添加剂量对肉鸡饲粮体外养分消化率和代谢能存在交互作用，22~42日龄饲粮的体外养分消化率和代谢能均高于1~21日龄饲粮。
Subjects: Biology >> Zoology submitted time 2018-12-24 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在利用单胃动物仿生消化系统（SDS-Ⅱ）研究外源淀粉酶对肉鸡玉米-豆粕型饲粮体外养分消化率和代谢能的影响，为准确评价饲用酶制剂的有效性提供依据。试验采用2×4双因素完全随机设计，参照我国《鸡饲养标准》（NY/T 33-2004）和NRC（1994）鸡营养需要配制肉鸡1~21日龄和22~42日龄玉米-豆粕型基础饲粮，并分别在2种基础饲粮中添加1 840、9 200和18 400 U/g的外源淀粉酶配制6种添加淀粉酶的饲粮，以不添加外源淀粉酶的2种基础饲粮作为对照，利用SDS-Ⅱ测定8种饲粮的体外干物质消化率（IVDMD）、体外表观粗蛋白质消化率（IVACPD）、体外标准化粗蛋白质消化率（IVSCPD）、体外淀粉消化率（IVSTD）、体外总能消化率（IVGED）和体外代谢能（IVME）。每种饲粮设5个重复，每个重复设1根消化管。结果表明：1）与对照组相比，1 840、9 200和18 400 U/g淀粉酶组饲粮胃阶段的IVDMD和IVGED均显著增加（P<0.05）；18 400 U/g淀粉酶组饲粮的IVME显著高于其他组（P<0.05）；22~42日龄饲粮的全消化道IVDMD、IVGED以及IVME均显著高于1~21日龄饲粮（P<0.05）。2）1 840和9 200 U/g淀粉酶组的全消化道IVACPD和IVSCPD均显著高于对照组（P<0.05），22~42日龄饲粮的全消化道IVACPD和IVSCPD显著高于1~21日龄饲粮（P<0.05）。3）8种饲粮的全消化道IVSTD均在99.40%以上，9 200和18 400 U/g淀粉酶组的全消化道IVSTD显著低于对照组（P<0.05），1~21日龄饲粮的全消化道IVSTD显著高于22~42日龄饲粮（P<0.05）。4）饲粮营养水平和淀粉酶添加剂量对肉鸡饲粮IVDMD、IVDGE、IVACPD、IVSCPD、IVSTD和IVME均存在交互作用（P<0.01）。在本试验条件下，外源淀粉酶的添加提高了肉鸡饲粮胃阶段的IVDMD、IVDGE，1 840和9 200 U/g外源淀粉酶提高了肉鸡饲粮的IVACPD、IVSCPD，18 400 U/g外源淀粉酶提高了肉鸡饲粮的IVME；玉米-豆粕型饲粮中淀粉几乎完全降解，外源淀粉酶对IVSTD的影响可以忽略；饲粮营养水平和外源淀粉酶添加剂量对肉鸡饲粮体外养分消化率和代谢能存在交互作用，22~42日龄饲粮的体外养分消化率和代谢能均高于1~21日龄饲粮。
Subjects: Biology >> Zoology submitted time 2018-12-24 Cooperative journals: 《动物营养学报》
Abstract：外源蛋白酶因可改善畜禽生长性能和健康，提高蛋白质、氨基酸等养分的消化率和节约饲料资源等特点而备受关注。外源蛋白酶对猪、鸡生长性能、养分消化率和健康受动物的年龄、饲粮类型、酶自身特性等因素的影响。本文概述了蛋白酶的分类、酶活性测定方法及其功能，侧重分析了外源蛋白酶对猪、鸡生长性能、养分消化率和健康等方面的影响，并讨论了添加外源蛋白酶对猪、鸡生产中环境排放的影响作用，以期为外源蛋白酶在畜禽养殖中的高效使用提供理论依据
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