混合盐胁迫对马蔺幼苗根系构型及生长量的影响

为探讨不同种类盐胁迫对马蔺幼苗生长状况的影响,采用室内培养的方法,研究总质量浓度为0.3%的NaCl、NaHCO₃单盐溶液及其不同配比的混合盐溶液胁迫对马蔺(Iris lactea var. chinensis)幼苗生长量、地上部干鲜重比值、地下部干鲜重比值以及根系构型的影响。结果表明,随着胁迫时间的延长,0.3%NaCl溶液对叶数和株高增长量的影响最小,其次为3种混合盐溶液,各处理在第14天时株高增幅达到最大。经0.3%NaHCO₃处理后的幼苗地上部干鲜重的比值为空白对照的2.17倍,地下部干鲜重则为空白对照的56.61%,随着混合溶液中NaHCO₃浓度的上升,地上部干鲜重比值表现出上升的趋势,地下部干鲜重比值则表现出下降的趋势。经35天处理后,0.3%NaHCO₃胁迫的马蔺幼苗根系总长、根系表面积较对照均显著下降,降幅分别为39.73%、26.08%,而各处理间的根系体积却无显著差异。研究结果显示,0.3%NaHCO₃溶液对马蔺幼苗的胁迫作用最强,2种单盐对根系的胁迫作用强于混合盐胁迫,而0.3%NaCl溶液对生长量的胁迫作用最弱。     

施肥对春青稞干物质积累、分配及产量的影响

为研究施肥对青稞干物质积累、分配及产量的调节作用,以‘藏青27’、‘QTB13’和‘QTB25’为试验材料,比较分析不同施肥处理下干物质积累、分配及产量的变化规律。结果表明：增加施肥量促进青稞分蘖期—成熟期的干物质积累及开花期和成熟期干物质向营养器官和籽粒的分配,提高了花前营养器官贮藏同化物转运量及对籽粒贡献率,降低了花后同化物输入籽粒量对籽粒贡献率。‘QTB13’和‘QTB25’在F₂条件下,更有利于干物质积累及向营养器官和穗部的分配,花后同化物输入籽粒量最大,产量也最大。‘藏青27’在F₃条件下,更有利于干物质积累及向营养器官和穗部的分配,花后同化物输入籽粒量和对籽粒贡献率最大,产量也最大。说明合理施肥有利于青稞干物质积累分配及产量提高。     

沙柳多元醇液化产物流变性能的研究

沙柳木粉在液化剂和催化剂的作用下制成的液化产物可生产制作聚氨酯、环氧树脂、胶黏剂等。研究沙柳液化产物的流变性能,可探索宏观流变性质与液体微观内部反应机理之间的关系,优化设备结构和加工工艺条件,对其高效利用有着重大意义。本试验将沙柳木粉在浓硫酸催化条件下进行多元醇液化,通过改变液化处理条件(反应时间、反应温度和催化剂用量)制备具有不同流变性能的沙柳液化产物。利用旋转型流变仪对所制备的沙柳液化产物进行流变性能测试和分析。沙柳木粉液化条件的单因素试验和正交试验分析结果表明:影响沙柳液化产物黏度的主要因素是反应时间,其次是反应温度和催化剂用量,最佳工艺条件为反应时间70 min、反应温度170℃、催化剂用量5%。在最佳工艺条件下,剪切速率为78.87 s-1时,黏度为0.26 Pa·s。红外光谱(FT-IR)分析得出,液化物中纤维素被大量降解,半纤维素和木质素部分降解,羟基增加,生成更多的反应活性官能团,此条件下液化反应更加充分,流体黏度较大。流变性能测试结果显示:稳态扫描测试时,黏度随剪切速率的增加逐渐减小,表现出剪切变稀的现象;剪切应力随着剪切速率的增加逐渐升高,表现出假塑性流体的性质。通过动态频率扫描曲线变化规律分析,储能模量和损耗模量随着角频率的升高而逐渐增加,复数黏度却随之减小。     

Analyzing the spatial allocation of Japan’s aid to China: A perspective from the relations between aid allocation stakeholders

While the spatial distribution of foreign aid has aroused a widespread academic interest, the existing research is limited mainly to the transnational level and lacks an analysis of aid allocation within a single recipient country. Moreover, more attention is paid to the factors influencing the aid allocation than to the interactions among different aid allocation stakeholders. To fill the research blank, this paper proposes a “three-party relationship model” to analyze the spatial allocation of aid within a recipient county, and uses the case of Japan's aid to China to validate the model. We find most of the aid has been allocated to the economic infrastructure, over time, and the key aid sector has shifted from economic infrastructure to social infrastructure and general environmental protection; The allocation characteristics of total aid and key aid sectors are various; The spatial allocation pattern of aid reflects an interaction between the donor (Japan) and the recipient country (China). The degree of importance of each aid allocation stakeholder is different at different stages of the total life cycle of aid, and the aid allocation stakeholder relationship in the three-party relationship model may be constantly reshaped during the allocation processes of aid in space.     

Sulodexide protects against hyperglycemia-induced retinal vascular injury via suppressing NOX4/NLRP3 pathway

AIM To investigate the effect of sulodexide (SDX) on high glucose-induced damage in retinal microvascular endothelial cells. METHODS (1) High-fat diet combined with intraperitoneal injection of streptozocin were used to induce type 2 diabetes mellitus (DM) followed by injection of saline or SDX in C57BL/6J male mice. Retinal microvascular leakage and density, and the protein levels of NLRP3 inflammasome-related proteins, zonula occludens-1 (ZO-1) and NADPH oxidase 4 (NOX4) were measured. (2) Human retinal microvascular endothelial cells (HRMECs) were treated with normal glucose or high glucose with or without SDX, and were further transfected with siRNA to knock down NOX4, or infected by adenovirus to over-express NOX4. The protein levels of ZO-1, VE-cadherin (VE-Cad), NOX4 and NLRP3 inflammasome-related proteins as well as the level of reactive oxygen species (ROS) were detected. RESULTS Treatment with SDX increased the protein level of ZO-1, attenuated retinal leakage and NLRP3 inflammasome activation, and enhanced the density of microvasculature and the number of ganglion cells in diabetic retinas. The protein levels of ZO-1 and VE-Cad were decreased, while the levels of NOX4, NLRP3 inflammasome-related proteins and ROS generation were increased in high glucose-treated HRMECs. Silencing of NOX4 inhibited high glucose-induced increases in NLRP3 inflammasome and ROS generation, and decreases in the protein levels of ZO-1 and VE-Cad. Over-expression of NOX4 significantly increased the levels of NLRP3 inflammasome-related proteins and ROS generation in HRMECs, and reduced the protein levels of ZO-1 and VE-Cad. Treatment with SDX partly reversed NOX4 over-expression-induced changes. CONCLUSION SDX alleviates hyperglycemia-induced retinal microvascular endothelial injury via inhibiting NOX4/ROS/NLRP3 pathways.     

Mechanism of elemene enhancing radiosensitivity of human glioma U251 cells

AIM To investigate the effect of elemene on the radiosensitivity of human glioma U251 cells and its mechanism. METHODS The U251 cells were used as a glioma model in vitro, and were exposed to different concentrations of elemene and different doses of radiation. The cell viability was measured by MTT assay, the apoptosis and cell cycle distribution were analyzed by flow cytometry, and the related protein levels were determined by Western blot. RESULTS Elemene inhibited the viability of U251 cells in vitro and enhanced the radiosensitivity of the cells. The cells in radiotherapy combined with elemene group had higher rates of early apoptosis, secondary necrosis and total cell death than those in radiation group. Elemene induced G₂/M phase arrest in the U251 cells. Elemene reduced the protein expression of cell division cycle protein 2 （Cdc2）, which resulted in the decrease in cyclin B1 expression induced by radiotherapy, thereby inhibiting the formation of cyclin B-Cdc2 complex. Elemene reduced Cdc2 activity by inhibiting the phosphorylation of Cdc2 protein at threonine 161, thereby inducing G₂/M phase arrest in the cells. It also mediated apoptosis by down-regulating survivin expression. CONCLUSION Elemene may increase the sensitivity of U251 cells to radiotherapy by down-regulating Cdc2 protein, decreasing cyclin B1 expression, inhibiting the formation of cylcin B-Cdc2 complex and down-regulating the expression of survivin.     

四川地区猕猴桃病毒1的RT-PCR检测及外壳蛋白基因序列分析

为了明确近期新西兰报道的侵染猕猴桃的新病毒——猕猴桃病毒1（Actinidia virus 1，AcV-1）在四川地区猕猴桃上的发生情况及其分子特性，采用RT-PCR对来自四川6个地区疑似感染病毒的90份猕猴桃主栽品种‘红阳’和‘金果’的叶片样品进行检测。结果表明，22份样品为AcV-1阳性，检出率为24.4%。将获得的5个AcV-1分离物和已报道的新西兰分离物K75的外壳蛋白（coat protein，CP）基因序列进行比对，结果表明，分离物间核苷酸序列和氨基酸序列的相似性分别为84.8% ~ 97.1%和89.7% ~ 99.6%，其中除邛崃分离物HYH5与新西兰分离物K75的核苷酸序列相似性较高（97.1%）外，其余4个分离物均低于91%。系统进化分析结果显示，这些分离物主要聚集在3个分支上，分离物HYH5与新西兰分离物K75位于同一分支，其余分离物位于另外2个分支。     

Seaweed polysaccharide mitigates intestinal barrier dysfunction induced by enterotoxigenic Escherichia coli through NF-κB pathway suppression in porcine intestinal epithelial cells

This study aimed to investigate the protective effects and underlying mechanism of seaweed polysaccharide (SWP) on intestinal epithelial barrier dysfunction induced by E. coli in an IPEC-J2 model. A preliminary study was done to screen optimum SWP concentrations by cell viability, cytotoxicity, apoptosis and proliferation evaluation. The regular study was conducted to evaluate the protective effects of SWP against E. coli challenge via the analysis of transepithelial electrical resistance (TEER), tight junction proteins, NF-κB signalling pathway, proinflammatory cytokines and the E. coli adhesion and invasion. Our results show that 4 h E. coli challenge down-regulated tight junction proteins expression, decreased TEER, activated NF-κB signalling pathway and increased proinflammatory response, which indicates that the E. coli infection model was well-established. Pre-treatment with 240 μg/ml SWP for 24 h alleviated the 4 h E. coli -induced intestinal epithelial barrier dysfunction, as evidenced by the up-regulated expression of Occludin, Claudin-1 and ZO-1 at both mRNA and protein level and the increased TEER of IPEC-J2 cells. Pre-incubation with 240 μg/ml SWP for 24 h inhibited the activation of the NF-κB signalling pathway by 4 h E. coli challenge, including the decreased mRNA expression of TLR-4, MyD88, IκBα, p-65, as well as the reduced ratio of protein expression of p-p65/p65. Also, pre-treatment with 240 μg/ml SWP for 24 h decreased proinflammatory response (IL-6 and TNF-α) induced by 4 h E. coli challenge and decreased the E. coli adhesion and invasion. In conclusion, SWP mitigated intestinal barrier dysfunction caused by E. coli through NF-κB pathway in IPEC-J2 cells and 240 μg/ml SWP exhibited better effect. Our results also provide a fundamental basis for SWP in reducing post-weaning diarrhoea of weaned piglets, especially under E. coli -infected or in-feed antibiotic-free conditions.     

Three SNPs within exons of INHA and ACVR2B genes are significantly associated with litter size in Dazu black goats

The aim of this study was to analyse the association between single-nucleotide polymorphisms within INHA and ACVR2B and litter size in Dazu black goats. In total, twenty-two SNPs were genotyped in 190 individuals by SNaPshot and resequencing. The results showed that three SNPs (SNP_1, SNP_12 and SNP_13 in this study) were detected to have significant additive genetic effect on the recorded goat litter size (p < .05). The SNP_1 (NC_030809.1), a non-synonymous substitution of G for T at chr2-g. 28314990 in the exon 2 of INHA gene (NM_001285606.1), resulted in homozygote 2 (HOM2) contributed 0.25 and heterozygote (HET) contributed 0.12 larger litter than homozygote 1 (HOM1). Meanwhile, SNP_12 (Chr22-g. 11721225 A > T) and SNP_13 (Chr22-g. 11721227 A > C) (NC_030829.1) simultaneously mutated at the first and third position of a triplet AAA (lysine, K) in the exon 4 of ACVR2B gene (XM_018066623.1) had estimated genetic effects of HOM1 (0.00) and HOM2 (0.03) larger than HET (−0.12). In conclusion, one SNPs (chr2-g. 28314990 T > G) within the exon 2 of INHA and two SNPs (Chr22-g. 11721225 A > T and Chr22-g. 11721227 A > C) i n the exon 4 of ACVR2B gene were highly recommended as candidate markers of litter size in Dazu black goats. A large-scale association study to assess the impact of these variants on litter size is still necessary.     

中国林产工业产业关联与波及效应分析——基于投入产出模型的国际比较

文中基于中国、美国、俄罗斯、印度、巴西、印度尼西亚6国2000—2014年投入产出数据，通过测算中间需求率、中间投入率、感应度系数和影响力系数，对林产工业产业关联与波及效应进行动态比较分析。研究结果表明:相较于其他国家，中国木材加工业、造纸业的中间产品型产业特征明显，对国民经济贡献程度较高，但同时也面临成为“瓶颈产业”的风险；中国家具制造业的最终需求型产业性质显著，受整体经济发展的拉动作用明显弱于其他国家。总体而言，中国林产工业对国民经济的推动作用整体上高于国民经济发展对其的拉动作用。需要重点提升木材加工业、家具制造业整体产业链竞争力，加大科研创新投入力度以提升产出效率，并进一步提高家具制造业整体产品的附加值。