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361.
柑橘叶片水分亏缺是影响柑橘生长发育的重要因素之一,为研究水分胁迫对柑橘含水率的影响,利用高光谱快速无损检测柑橘叶片含水率,并应用伪彩色处理实现含水率可视化。收集100片柑橘叶片,使用烘干法得到鲜叶和烘干叶片一共500个不同梯度含水率的数据样本,将样本按7∶3的比例划分为训练集(350个样本)和测试集(150个样本),使用决定系数(R2)和均方根误差(RMSE)来评估模型预测的好坏。采用卷积神经网络(CNN)对高光谱数据进行预测,CNN模型使用一维卷积核,一共三层卷积池化层,使用RELU激活函数激活,输出层采用linear激活函数回归预测,使用nadam算法对模型进行优化更新,迭代次数为1 000次;将原始光谱数据和SG,MSC和SNV三种预处理后的光谱数据,与全波段、CARS筛选的特征波段、PCA提取的特征波段组合,导入CNN模型,确定最佳模型为原始光谱数据的CARS-CNN,训练集的R2c和RMSEC分别为0.967 9和0.016 3,测试集的R2v和RMSEV分别为0.9...  相似文献   
362.
建立了色谱指纹图谱的双定性双定量相似度评价法,并应用于银杏达莫注射液的高效液相色谱(HPLC)指纹图谱的评价。采用反相HPLC,以芦丁为参照物峰,确定了41个共有峰,建立了银杏达莫注射液的对照指纹图谱。以双定性相似度S和S′、双定量相似度C和P评价银杏达莫注射液的HPLC指纹图谱,分别考察在大峰缺失和小峰缺失两种情况下,4个相似度指标的变化特征。S能反映化学成分的分布比例,受大峰影响严重,无法反映小峰的丢失; S′对所有指纹峰等权,反映小峰缺失灵敏,二者构成双定性相似度。C能反映样品共有峰的总体含量,但受大峰影响严重,无法反映小峰的缺失; P对所有峰积分值等权,能较好地反映小峰的变动,二者构成双定量相似度。因此,由S与S′、C与P构成的双定性双定量相似度法能同时监测大峰和小峰的变动与缺失,能准确地解决色谱指纹图谱的宏观定性和定量评价问题。同时还提出了方向余弦作为对照指纹图谱的特征指纹的概念和分解相似度的概念,以此考察了各指纹峰对相似度贡献的大小及其在不同程度缺失时4种相似度的变化情况。所建立的HPLC对照指纹图谱可用于银杏达莫注射液的质量控制。  相似文献   
363.
可见/近红外光谱分析技术鉴别转基因番茄叶   总被引:6,自引:0,他引:6  
用可见/近红外光谱(Vis-NIR spectrum)漫反射方式对转基因番茄叶和非转基因番茄叶进行了快速、无损的定性分析。实验共对68个样品(转基因38个,非转基因30个)进行分类,用TQ 6.2.1光谱分析软件中集成的判别分析(Discriminant analysis)和偏最小二乘回归法(PLS)建立校正和预测模型。研究对比了不同光谱预处理方法(微分处理和多元散射校正(MSC))对分类结果的影响。实验结果发现用判别分析较最小二乘法判别结果较好,用InGaAs检测器获得的光谱经MSC后的分类结果最好,分类正确率为89.7%(转基因番茄叶86.8%,非转基因番茄叶93.3%)。结果表明VIS-NIR可以作为一种快速的无损检测方法鉴别转基因和非转基因番茄叶。  相似文献   
364.
扫描次数对番茄叶漫反射光谱和模型精度的影响研究   总被引:5,自引:0,他引:5  
近红外光谱分析技术因其诸多优点成为近年来发展最快的定量和定性分析技术之一,它是依据有机分子中的含氢基团(C—H, O—H, N—H)振动的合频与各级倍频的吸收获得信息。但是,近红外光谱易受到光谱仪的工作状态和扫描时各种参数的设置,如波长的准确性、仪器的分辨率、噪声、扫描次数、样品粒度的均匀性等的影响。为了给建立实际模型时选择最佳的测量条件提供依据,文章以番茄叶为研究对象,分析了扫描次数对番茄叶漫反射光谱和叶绿素定量模型精度的影响。结果发现扫描次数对番茄叶漫反射光谱和模型精度有较大的影响。随着扫描次数的增加,近红外光谱的均方根噪声的方差值逐渐变小。扫描次数越多,光谱的质量较高,但是仪器产生的系统误差也会增大;扫描次数越少, 光谱的质量较差,但是光谱较为光滑,系统的误差较小。在128次扫描次数下,叶绿素定量模型的决定系数较高,但是模型不稳定。当扫描次数为32时,模型的决定系数较低,但该模型比较稳定,检测时间也较短。同时,不同扫描次数下所建模型都用于预测叶绿素含量,发现没有显著差异(α=0.05)。在采集光谱建立模型时,应考虑综合因素选择合适的扫描次数。  相似文献   
365.
In the current scenario, people are highly concerned regarding their health and constantly desire a healthy and nutritious diet. Moringa oleifera is traditionally known as saijhan or drumstick tree. The plant is native to tropical Asia and thus found in various parts of the country India. Being a nutrient-rich plant, Moringa leaves play a vital role in the treatment of malnutrition. It also has anti-inflammatory, anti-spasmodic, anti-asthmatic, anti-ulcer, hypocholesterolemic, and hypoglycemic properties. Fresh fruits have also been desirable and in growing demand, because of healthy food consumption trends worldwide. The following study was undertaken to provide nutrient-rich food in the busy growing lifestyle. Thus, in this study, preparation and optimization of the Moringa leaf powder have been done. The final product is developed by incorporating Moringa leaf powder into pomegranate juice to prepare a ready-to-serve (RTS) beverage. On the basis of this study, it concluded that 100:2:2.8:0.2 concentration of Pomegranate, Moringa oleifera leaf powder, Sugar, Citric Acid is suitable for the preparation of Ready to Serve Beverage. In this study, proximate analysis and sensory evaluation have been performed to understand the overall acceptability of the final product.  相似文献   
366.
《Arabian Journal of Chemistry》2020,13(11):7773-7797
Guava is known for its hypoglycemic, antivirus, antibacterial, anti-inflammatory, antioxidant, and antitumor properties. In this study, triterpenoids, sesquiterpenes, and flavonoids were examined as potential targets of constituents of guava leaves. Our study was aimed to reveal the antitumor mechanism and construct the network pharmacology network of guava leaf constituents and lung cancer. The potential targets of guava leaf constituents were searched in target databases, while the disease genes were searched in the GeneCards database. The common targets of drugs and diseases were screened out. A network map was constructed by the Cytoscape software, and the GO and KEGG pathways were analyzed. The existing cases were studied by SystemsDock molecular docking and cBioPortal tumor database study. Among the 66 chemical constituents of guava leaves, 153 of their targets were the lung cancer genes involved in many signaling pathways, such as the PI3K-Akt signaling pathway, in small cell lung cancer and non-small cell lung cancer. There was a binding activity between ligand compounds and receptor proteins. Guava leaves inhibited tumor through a gene regulatory network, and may play an important role in gene-targeting therapy. Through network pharmacology, we found that guava leaves had potential targets that interacted with various tumors, regulating the signaling pathways of cancers. This study preliminarily verified the pharmacological basis and the mechanism of the antitumor effect of guava leaves, providing a foundation for further research.  相似文献   
367.
Abelmoschus manihot (L.) Medic (AM), called Huangshukui in Chinese, is a widely used medicinal plant. Each part of AM has medicinal value, including Abelmoschi Radix (AR), Abelmoschi Herba (AH), Abelmoschi Folium (AF), Abelmoschi Corolla (AC), and Abelmoschi Semen (AS). However, only AC is documented in the Chinese Pharmacopoeia. In order to investigate whether there is any difference between AC and the other parts of AM, an analytical method based on ultra-fast performance liquid chromatography coupled with triple quadrupole-linear ion trap mass spectrometry (UFLC-QTRAP-MS/MS) was established for the simultaneous determination of 35 constituents in different parts of AM. Moreover, principal components analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were applied to classify and evaluate the different parts of AM based on the content of the 35 constituents. The total contents of the 35 constituents in AC were significantly higher than in the other parts of AM and the results revealed significant differences between AC and the other parts of AM. Eight constituents were remarkably related to the sample classifications. This research does not just provide the basic information for revealing the distribution patterns in different parts of AM from the same origin, but also complements some of the scientific data for the comprehensive quality evaluation of AC.  相似文献   
368.
This study aimed to investigate the chemical composition of the leaf essential oil from Ivoirian Isolona dewevrei. A combination of chromatographic and spectroscopic techniques (GC(RI), GC-MS and 13C-NMR) was used to analyze two oil samples (S1 and S2). Detailed analysis by repetitive column chromatography (CC) of essential oil sample S2 was performed, leading to the isolation of four compounds. Their structures were elucidated by QTOF-MS, 1D and 2D-NMR as (10βH)-1β,8β-oxido-cadin-4-ene (38), 4-methylene-(7αH)-germacra-1(10),5-dien-8β-ol (cis-germacrene D-8-ol) (52), 4-methylene-(7αH)-germacra-1(10),5-dien-8α-ol (trans-germacrene D-8-ol) (53) and cadina-1(10),4-dien-8β-ol (56). Compounds 38, 52 and 53 are new, whereas NMR data of 56 are reported for the first time. Lastly, 57 constituents accounting for 95.5% (S1) and 97.1% (S2) of the whole compositions were identified. Samples S1 and S2 were dominated by germacrene D (23.6 and 20.5%, respectively), followed by germacrene D-8-one (8.9 and 8.7%), (10βH)-1β,8β-oxido-cadin-4-ene (7.3 and 8.7), 4-methylene-(7αH)-germacra-1(10),5-dien-8β-ol (7.8 and 7.4%) and cadina-1(10),4-dien-8β-ol (7.6 and 7.2%). Leaves from I. dewevrei produced sesquiterpene-rich essential oil with an original chemical composition, involving various compounds reported for the first time among the main components. Integrated analysis by GC(RI), GC-MS and 13C-NMR appeared fruitful for the knowledge of such a complex essential oil.  相似文献   
369.
Mulberry (Morus alba L.) leaves (MLs), originally used to feed silkworms, have recently been recognized as a food ingredient containing health-beneficial, bioactive compounds. In this study, the extrusion process was applied for the enhancement of the amount of extractable flavonoids from MLs. Extrusion conditions were optimized by water solubility index, total phenolic content, and total flavonoid content (TF) using response surface methodology, and antioxidative stress activities were evaluated in macrophage cells. According to the significance of regression coefficients of TF, the optimal extrusion parameters were set as barrel temperature of 114 °C, moisture feed content of 20%, and screw speed of 232 rpm. Under these conditions, the TF of extruded ML reached to 0.91% and improved by 63% compared with raw ML. Fifteen flavonoids were analyzed using ultra-high-performance liquid chromatograph coupled with photodiode array detection and quadrupole time-of-flight mass spectrometry (UPLC-PDA-QTOF/MS), and the extrusion resulted in increases in quercetin-3-gentiobioside, quercetin-3,7-di-O-glucoside, kaempferol-3,7-di-O-glucoside, rutin, isoquercitrin, and moragrol C. Besides, regarding antioxidative activity, extruded ML water extract inhibited the production of H2O2-induced reactive oxygen species and attenuated nuclear morphology alterations in macrophage cells. The findings of this study should be useful in food processing design to improve the extractable functional compounds in MLs.  相似文献   
370.
In recent years, researchers have used bionanotechnology techniques as cost‐effective and eco‐friendly routes to fabricate nanoparticles. The present study confirms the ability of aqueous extract of Falcaria vulgaris for the biosynthesis of iron nanoparticles (FeNPs@F. vulgaris). Also, in this study, we showed the antioxidant, cytotoxicity, cutaneous wound healing, antibacterial, and antifungal activities of these nanoparticles. FeNPs@F. vulgaris were characterized by UV, FT‐IR, XRD, FE‐SEM, and TEM analysis. According to the XRD analysis, 25.3 nm was measured for the crystal size of nanoparticles. FE‐SEM and TEM images exhibited a uniform spherical morphology and average diameters of 25 nm for the biosynthesized nanoparticles. FTIR results offered protein and polysaccharides in F. vulgaris were the sources of reducing power, reducing iron ions to FeNPs@F. vulgaris. In vivo design, FeNPs@F. vulgaris ointment remarkably reduced (p ≤ 0.01) the wound area, total cells, neutrophil, and lymphocyte and substantially increased (p ≤ 0.01) the wound contracture, vessel, hydroxyl proline, hexosamine, hexuronic acid, fibrocyte, and fibrocytes/fibroblast rate compared to other groups in rats. Also, FeNPs@F. vulgaris indicated potential antioxidant activity against DPPH, antifungal potentials against Candida glabrata, Candida albicans, Candida krusei, and Candida guilliermondii, antibacterial properties against Gram‐positive bacteria (Streptococcus pneumonia, Staphylococcus aureus, and Bacillus subtilis) and Gram‐negative bacteria (Salmonella typhimurium, Pseudomonas aeruginosa, and Escherichia coli O157:H7) without any cytotoxicity effect against human umbilical vein endothelial cells. Finally, the results showed the useful antioxidant, non‐cytotoxic, cutaneous wound healing, antifungal, and antibacterial effects of FeNPs@F. vulgaris.  相似文献   
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