Investigation of the Potential Health Benefits as Lipase Inhibitor and Antioxidant of <Emphasis Type="Italic">Leopoldia comosa</Emphasis> (L.) Parl.: Variability of Chemical Composition of Wild and Cultivated Bulbs

There is a great interest in the nutritional value of vegetables and fruits and how the habitat affects nutritive and biological properties. In vitro studies here reported were performed to evaluate the inhibitory activity of formulations from edible plant on pancreatic lipase. The aim of this study was also to evaluate the biovariability of L. comosa (L.) Parl. bulbs from Italy. The wild bulbs were compared with the same cultivated species that are commonly commercialized to identify samples with the best quality for a potential therapeutic application. Hydroalcoholic extract and polar fraction of wild bulbs showed a very important pancreatic lipase inhibitory activity, with IC₅₀ values of 0.166 ± 0.005 and 0.153 ± 0.005 mg/mL, respectively. In order to characterize the extracts, gas chromatography associated with mass spectrometry (GC/MS) analysis was performed, revealing the predominance of palmitic acid. Phenolic and flavonoid composition was also evaluated. L. comosa extract obtained from wild bulbs demonstrated both antioxidant and anti-obesity activities that might be attributed to a wide range of present phenolic compounds.     

Mapping QTLs using a novel source of salinity tolerance from Hasawi and their interaction with environments in rice

Background

Salinity is one of the most severe and widespread abiotic stresses that affect rice production. The identification of major-effect quantitative trait loci (QTLs) for traits related to salinity tolerance and understanding of QTL × environment interactions (QEIs) can help in more precise and faster development of salinity-tolerant rice varieties through marker-assisted breeding. Recombinant inbred lines (RILs) derived from IR29/Hasawi (a novel source of salinity) were screened for salinity tolerance in the IRRI phytotron in the Philippines (E1) and in two other diverse environments in Senegal (E2) and Tanzania (E3). QTLs were mapped for traits related to salinity tolerance at the seedling stage.

Results

The RILs were genotyped using 194 polymorphic SNPs (single nucleotide polymorphisms). After removing segregation distortion markers (SDM), a total of 145 and 135 SNPs were used to construct a genetic linkage map with a length of 1655 and 1662 cM, with an average marker density of 11.4 cM in E1 and 12.3 cM in E2 and E3, respectively. A total of 34 QTLs were identified on 10 chromosomes for five traits using ICIM-ADD and segregation distortion locus (SDL) mapping (IM-ADD) under salinity stress across environments. Eight major genomic regions on chromosome 1 between 170 and 175 cM (qSES1.3, qSES1.4, qSL1.2, qSL1.3, qRL1.1, qRL1.2, qFWsht1.2, qDWsht1.2), chromosome 4 at 32 cM (qSES4.1, qFWsht4.2, qDWsht4.2), chromosome 6 at 115 cM (qFWsht6.1, qDWsht6.1), chromosome 8 at 105 cM (qFWsht8.1, qDWsht8.1), and chromosome 12 at 78 cM (qFWsht12.1, qDWsht12.1) have co-localized QTLs for the multiple traits that might be governing seedling stage salinity tolerance through multiple traits in different phenotyping environments, thus suggesting these as hot spots for tolerance of salinity. Forty-nine and 30 significant pair-wise epistatic interactions were detected between QTL-linked and QTL-unlinked regions using single-environment and multi-environment analyses.

Conclusions

The identification of genomic regions for salinity tolerance in the RILs showed that Hasawi possesses alleles that are novel for salinity tolerance. The common regions for the multiple QTLs across environments as co-localized regions on chromosomes 1, 4, 6, 8, and 12 could be due to linkage or pleiotropic effect, which might be helpful for multiple QTL introgression for marker-assisted breeding programs to improve the salinity tolerance of adaptive and popular but otherwise salinity-sensitive rice varieties.

     

Investigation of mechanical properties of developed antimicrobial PPsuture/Ag nanocomposite

In order to prevent surgical complications due to microbial infections, we have developed polypropylene suture grafted with silver nanoparticles (PPsuture/Ag nanocomposite) by a simple immersion procedure. Physical and mechanical properties of developed suture are investigated. Suture surface characteristics are examined by scanning electron microscopy (SEM) imaging and atomic force microscopy (AFM). Silver content on suture surface was determined by Inductively coupled plasma atomic emission spectroscopy (ICP-AES). The mechanical properties of developed antibacterial PP suture/Ag were studied. We note that proposed silver coating method has not affected mechanical performances of suture. Antimicrobial performances of PP suture/Ag nanocomposites against S. aureus and E. coli colonies were also investigated.     

基于实时性优化的内燃机燃烧分析系统研究

采用缸压传感器、数据采集卡、光电编码器和Lab VIEW软件,搭建在线缸压采集和实时燃烧分析系统平台,研究HCCI和RCCI燃烧模式的循环波动特性。针对单循环缸压测量过程中的通道效应干扰,基于频谱分析,采用FFT、线性插值法和IFFT等方法相结合的滤波方式,实现共振峰的在线自适应识别与实时滤波,较好地减少了单循环缸压的干扰误差,使单循环的实时燃烧分析成为可能。随后,基于实时滤波后的缸压曲线,计算得到内燃机的最大压力升高率、燃烧放热率、爆发压力等重要燃烧参数。利用程序算法中同步性良好的生产者/消费者运算模式提高数据的共享能力,实现了数据实时运算与数据快速储存的并行处理,提高了燃烧计算的实时性;针对发动机不同工作阶段采用了不同精度层次的计算方法,减少了进排气、压缩和膨胀阶段的计算耗时,在计算量较大的燃烧放热率计算部分,通过适当简化计算公式和公式节点运算模块来提高燃烧系统的实时性。最后,分析了燃烧分析系统的实时性,并进行了燃烧分析系统的实验验证。     

外源NO及反向调控PEG胁迫下苜蓿萌发种子抗氧化酶及其同工酶动态的研究

以紫花苜蓿为材料,用一氧化氮供体硝普钠(SNP)及一氧化氮清除剂c-PTIO对苜蓿种子进行浸种处理,采用分光光度法和同工酶电泳技术来研究外源NO及反向调控对PEG胁迫下紫花苜蓿抗氧化酶活性及其同工酶的影响,并探讨NO调控苜蓿种子耐旱性的生理机制。结果表明:PEG胁迫下外施0.1 mmol·L^-1 SNP,第6天时较PEG处理POD活性降低了32.72%;第4天时SOD、CAT活性较PEG处理升高了10.48%、23.60%,有效缓解了PEG对紫花苜蓿萌发中种子的氧化损伤,提高其抗氧化能力。PEG胁迫下添加 c-PTIO抑制了苜蓿萌发期的抗氧化系统活性。从同工酶的谱带数量和强弱来看,POD同工酶各区带活力均随PEG胁迫时间的延长而增加,在第2天酶带只有1条,而第4天酶带呈现9条;SOD和CAT同工酶表达量变化不显著,但酶带强弱有一定变化,S3酶带随处理时间的延长表达量逐渐减弱;CAT同工酶谱带则一直保持2条带,无明显强弱变化。因此,外源NO在PEG胁迫下紫花苜蓿萌发中抗氧化酶快速响应并在维护氧自由基代谢平衡中起重要保护作用。     

Conductive 3D structure nanofibrous scaffolds for spinal cord regeneration

The complex nature of spinal cord injuries has provided much inspiration for the design of novel biomaterials and scaffolds which are capable of stimulating neural tissue repair strategies. Recently, conductive polymers have gained much attention for improving the nerve regeneration. In our previous study, a three-dimensional (3D) structure with reliable performance was achieved for electrospun scaffolds. The main purpose in the current study is formation of electrical excitable 3D scaffolds by appending polyaniline (PANI) to biocompatible polymers. In this paper, an attempt was made to develop conductive nanofibrous scaffolds, which can simultaneously present both electrical and topographical cues to cells. By using a proper 3D structure, two kinds of conductive scaffolds are compared with a non-conductive scaffold. The 3D nanofibrous core-sheath scaffolds, which are conductive, were prepared with nanorough sheath and aligned core. Two different sheath polymers, including poly(lactic-co-glycolic acid) PLGA and PLGA/PANI, with identical PCL/PANI cores were fabricated. Nanofibers of PCL and PLGA blends with PANI have fiber diameters of 234±60.8 nm and 770±166.6 nm, and conductivity of 3.17×10^-5 S/cm and 4.29×10^-5 S/cm, respectively. The cell proliferation evaluation of nerve cells on these two conductive scaffolds and previous non-conductive scaffolds (PLGA) indicate that the first conductive scaffold (PCL/ PANI-PLGA) could be more effective for nerve tissue regeneration. Locomotor scores of grafted animals by developed scaffolds showed significant performance of non-conductive 3D scaffolds. Moreover, the animal studies indicated the ability of two new types of conductive scaffolds as spinal cord regeneration candidates.     

Effect of nitrogen root zone fertilization on rice yield,uptake and utilization of macronutrient in lower reaches of Yangtze River,China

Improper application of nitrogen (N) has led to high N losses and low N use efficiency in the lower reaches of Yangtze River in China. An effective method to solve such problems is the deep fertilized N in root zone (RZF). Limited information is available on the effect of RZF on the uptake of macronutrients (N, P and K) and rice yield. Field experiments, conducted from 2014 to 2015, compared the farmer fertilizer practice (FFP, with 225 kg ha^?1 of N, split into three doses) and RZF using the same rate but placing N 5 cm away from rice roots in holes 10 cm deep (RZF10) or 5 cm deep (RZF5) as a single application. The highest mean yield (10.0 t ha^?1) was obtained in RZF10, which was 19.5% more than that in FFP. Root zone fertilization of urea (whether 10 cm deep or 5 cm deep) resulted in greater accumulation of N, P and K in stem, leaf sheaths, leaf blades and grains compared to that in FFP in sandy and in loam soils. The uptake of N, P and K was the highest in RZF10 (average at 176.7, 66.2 and 179.1 kg ha^?1, respectively), higher than that in FFP by 45.0, 17.0 and 22.6%, respectively. N apparent recovery efficiency was markedly higher in RZF10 (53.1%) than in FFP (27.5%). RZF10 significantly increased the N, P, K uptake compared with FFP under different N rates in both sandy and loam soils. These results suggest that the N, P and K input amount should be re-determined under RZF.     

不同氮肥水平下蚯蚓粪施用对水稻生长特性及产量的影响

以两优培九为材料,采用大田微区试验,研究不同氮肥水平(N1,9 g/m~2;N2,12 g/m~2;N3,15 g/m~2)下不同蚯蚓粪施用量(EC0,0;EC_1,16.88 kg/m~2;EC_2,33.76 kg/m~2)对水稻生长及产量形成的影响。结果表明,移栽40 d后EC_2和EC_1处理的茎蘖数均显著高于EC0(P0.05);幼穗分化期和乳熟期EC0处理的SPAD值均显著低于EC_1和EC_2处理(P0.05);齐穗期EC0处理的叶面积指数分别比EC_1和EC_2处理低32.7%和80.7%,地上部总干物质量分别比EC_1和EC_2处理低30.6%和59.8%;成熟期有效穗数、地上部干物质量和水稻产量均表现为EC_2EC_1EC0,EC_2和EC_1处理的有效穗数分别比EC0处理多41.5%和21.3%、地上部干物质量分别比EC0处理高47.7%和25.8%、产量分别比EC0处理高35.4%和34.3%。由此可见,施用蚯蚓粪便可促进水稻分蘖,提高水稻叶面积、SPAD值和地上部干物质量,进而提高水稻籽粒产量。     

不同施氮量对盐碱地水稻产量及品质的影响

以南粳9108为试验材料,研究了施氮量对盐碱地水稻产量及品质的影响。结果表明,在一定范围内,水稻产量随着施氮量的增加而增加,在施氮量为20 kg/667 m~2时产量最高;盐碱地条件下,增施氮肥会增加稻米的垩白粒率、垩白度和蛋白质含量,降低直链淀粉含量;此外,施氮量的增加还会显著降低稻米的蒸煮品质与食味品质。     

基于GIS与RS的北方防沙屏障带生态系统格局演变

研究北方防沙屏障带生态系统格局演变特征,对加强屏障带建设、改善生态环境具有重要意义。以北方防沙屏障带为研究区,根据2005、2010、2015年MODIS遥感影像,将北方防沙屏障带生态系统类型划分为森林、草地、湿地、农田、城镇、荒漠和裸地7类。采用空间统计、转移矩阵、景观指数分析法、PNTIL模型等方法,对北方防沙屏障带2005—2015年生态系统类型时空演变特征进行分析。结果表明,2005—2015年北方防沙屏障带生态系统整体呈稳定状态;从分屏障带看,内蒙古防沙屏障带荒漠面积明显减少,塔里木防沙屏障带森林面积迅速增加,而河西走廊防沙屏障带草地面积明显增加;从正/逆转换方向来看,屏障带内农田、城镇、荒漠及裸地生态系统正向转换率高于逆向转换率。10年间,在景观水平上,北方防沙屏障带斑块数量、斑块密度呈减少趋势;在类型水平上荒漠景观整体呈现破碎化萎缩的趋势特征,森林、草地向形状简单化的方向发展。研究表明,2005—2015年,北方防沙屏障带生态总体向好,治沙效果明显,但局部仍面临较大压力。