Steroid saponins and other constituents from the rhizome of Trillium tschonoskii Maxim and their cytotoxic activity

Fourteen compounds were isolated from the rhizome of Trillium tschonoskii Maxim. By spectroscopic analysis, these compounds were established as Gracillin (1), Paris saponins V (2), Paris saponins VI (3), Paris saponins H (4), Paris saponins VII (5), (25R)-17α-hydroxy-5-en-3-O-a-L-arabinofuranosyl-(1→2)-β-Dglucopyranoside (6), (25R)-26-[β-D-glucopyanosyl]-17α,22β-dihydroxy-5-en-3-O-a-L-rhamnopyranosyl- (1→2)-β-D-glucopyranoside (7), Kaempferol-3-O-β-D-rutinoside (8), Quercetin (9), Quercetin-3-O-β-D-galactoside (10), Daucosterol (11), Stigmasterol-3-O-β-D-glucopyranoside (12), 3, 5-Di-O-caffeoyl quinic acid (13), and n-Hexadecanoic acid (14). By GC-MS analysis of the CH2Cl2 extract from Trillium tschonoskii Maxim, twenty compouns were identified, representing 91 % of the area. The cytotoxicity of compounds 1-14 on mouse A549 cells were evaluated.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Steroid saponins and other constituents from the rhizome of Trillium tschonoskii Maxim and their cytotoxic activity

Fourteen compounds were isolated from the rhizome of Trillium tschonoskii Maxim. By spectroscopic analysis, these compounds were established as Gracillin (1), Paris saponins V (2), Paris saponins VI (3), Paris saponins H (4), Paris saponins VII (5), (25R)-17α-hydroxy-5-en-3-O-a-L-arabinofuranosyl-(1→2)-β-Dglucopyranoside (6), (25R)-26-[β-D-glucopyanosyl]-17α,22β-dihydroxy-5-en-3-O-a-L-rhamnopyranosyl- (1→2)-β-D-glucopyranoside (7), Kaempferol-3-O-β-D-rutinoside (8), Quercetin (9), Quercetin-3-O-β-D-galactoside (10), Daucosterol (11), Stigmasterol-3-O-β-D-glucopyranoside (12), 3, 5-Di-O-caffeoyl quinic acid (13), and n-Hexadecanoic acid (14). By GC-MS analysis of the CH2Cl2 extract from Trillium tschonoskii Maxim, twenty compouns were identified, representing 91 % of the area. The cytotoxicity of compounds 1-14 on mouse A549 cells were evaluated.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Lepidopteran wing scales contain abundant cross-linked film-forming histidine-rich cuticular proteins

Scales are symbolic characteristic of Lepidoptera; however, nothing is known about the contribution of cuticular proteins (CPs) to the complex patterning of lepidopteran scales. This is because scales are resistant to solubilization, thus hindering molecular studies. Here we succeeded in dissolving developing wing scales from Bombyx mori, allowing analysis of their protein composition. We identified a distinctive class of histidine rich (His-rich) CPs (6%–45%) from developing lepidopteran scales by LC-MS/MS. Functional studies using RNAi revealed CPs with different histidine content play distinct and critical roles in constructing the microstructure of the scale surface. Moreover, we successfully synthesized films in vitro by crosslinking a 45% His-rich CP (BmorCPR152) with laccase2 using N-acetyl- dopamine or N-β-alanyl-dopamine as the substrate. This molecular study of scales provides fundamental information about how such a fine microstructure is constructed and insights into the potential application of CPs as new biomaterials

A NAC-EXPANSIN module enhances maize kernel size by controlling nucellus elimination

Maize early endosperm development is initiated in coordination with elimination of maternal nucellar tissues. However, the underlying mechanisms are largely unknown. Here, we characterize a major quantitative trait locus for maize kernel size and weight that encodes an EXPANSIN gene, ZmEXPB15. The encoded β-expansin protein is expressed specifically in nucellus, and positively controls kernel size and weight by promoting nucellus elimination. We further show that two nucellus-enriched transcription factors (TFs), ZmNAC11 and ZmNAC29, activate ZmEXPB15 expression. Accordingly, these two TFs also promote kernel size and weight through nucellus elimination regulation, and genetic analyses support their interaction with ZmEXPB15. Importantly, hybrids derived from a ZmEXPB15 overexpression line have increased kernel weight, demonstrates its potential value in breeding. Together, we reveal a pathway modulating the cellular processes of maternal nucellus elimination and early endosperm development, and an approach to improve kernel weight

Multi-Disturbance Observers-Based Nonlinear Control Scheme for Wire Rope Tension Control of Hoisting Systems with Backstepping

The objective of this paper is to pursue a wire rope control methodology for reducing the tension difference between two wire ropes of a hoisting system. As we know, complicated disturbances exist in the complex electro-hydraulic hoisting system, notably, some of these disturbances are coupled, such as high-speed airflow disturbances, structure vibrations and vibrations in flexible wire ropes. Furthermore, there are model errors in force modeling due to the Coulomb friction between two wire ropes and two moveable head sheaves in the real physical hoisting systems. To eliminate disturbances, two types of disturbance observers (DOs) are employed: a traditional disturbance observer (TDO) and a coupled disturbance observer (CDO), both of which are utilized to estimate and compensate for the Coulomb friction and coupled disturbances online. As a result, a nonlinear backstepping control scheme is presented with estimation values from the TDO and the CDO. The experiment’s results demonstrate the effectiveness of the proposed control methodology

Boosting Face Recognition under Drastic Views Using a Pose AutoAugment Manner

Face recognition under drastic pose drops rapidly due to the limited samples during the model training. In this paper, we propose a pose-autoaugment face recognition framework (PAFR) based on the training of a Convolutional Neural Network (CNN) with multi-view face augmentation. The proposed framework consists of three parts: face augmentation, CNN training, and face matching. The face augmentation part is composed of pose autoaugment and background appending for increasing the pose variations of each subject. In the second part, we train a CNN model with the generated facial images to enhance the pose-invariant feature extraction. In the third part, we concatenate the feature vectors of each face and its horizontally flipped face from the trained CNN model to obtain a robust feature. The correlation score between the two faces is computed by the cosine similarity of their robust features. Comparable experiments are demonstrated on Bosphorus and CASIA-3D databases

A Coarse-to-Fine Approach for 3D Facial Landmarking by Using Deep Feature Fusion

Facial landmarking locates the key facial feature points on facial data, which provides not only information on semantic facial structures, but also prior knowledge for other kinds of facial analysis. However, most of the existing works still focus on the 2D facial image which may suffer from lighting condition variations. In order to address this limitation, this paper presents a coarse-to-fine approach to accurately and automatically locate the facial landmarks by using deep feature fusion on 3D facial geometry data. Specifically, the 3D data is converted to 2D attribute maps firstly. Then, the global estimation network is trained to predict facial landmarks roughly by feeding the fused CNN (Convolutional Neural Network) features extracted from facial attribute maps. After that, input the local fused CNN features extracted from the local patch around each landmark estimated previously, and other local models are trained separately to refine the locations. Tested on the Bosphorus and BU-3DFE datasets, the experimental results demonstrated effectiveness and accuracy of the proposed method for locating facial landmarks. Compared with existed methods, our results have achieved state-of-the-art performance

Study on Solvent Extraction of Rare Earth Elements from Leaching Solution of Coal Fly Ash by P204

Due to the increasing demand for rare earth elements (REE) resources in the market and the shortage of their direct sources, the research on REE in coal fly ash (CFA) has attracted the increasing attention of scholars because of its high content of rare earth. To extract and separate REE from the leaching solution of CFA, the method of solvent extraction after acid leaching is usually adopted. In this paper, the leaching solution of coal fly ash from Panbei, south China, with an average REE content of 478 μg/g, was taken as the research object. The extracted di-2-Ethylhexyl phosphonic acid (P204) was used to explore the solvent extraction effect and mechanism. When performed with the conditions: pH value of 2.1, oil-water ratio (O/A) of 1, extraction time of 25 min, solvent concentration of 6% and temperature of 30 ℃, the extraction rates of La, Ce, Pr, Nd, and Y were 89.16%, 94.11%, 95.56%, 96.33%, and 99.80%, respectively. It was indicated that the P204 extraction system separated REE well from the aqueous phase. The structure of the extraction complex was deduced by taking yttrium as an object of analysis, and the extraction mechanism equation was determined by using the slope method. In this extraction system, the molecular formula of the complex is YCl2(HA2) and the enthalpy change (△H) is +86.68 kJ/mol, which provides theoretical guidance for the extraction of REE in industrial production

Heteroepitaxial Growth of 3C-SiC Films on Maskless Patterned Silicon Substrates

Heteroepitaxial growth of 3C-SiC on patterned Si substrates by low pressure chemical vapor deposition (LPCVD) has been investigated to improve the crystal quality of 3C-SiC films. Si substrates were patterned with parallel lines, 1 to 10μm wide and spaced 1 to 10μm apart, which was carried out by photolithography and reactive ion etching. Growth behavior on the patterned substrates was systematically studied by scanning electron microscopy (SEM). An air gap structure and a spherical shape were formed on the patterned Si substrates with different dimensions. The air gap formed after coalescence reduced the stress in the 3C-SiC films, solving the wafer warp and making it possible to grow thicker films. XRD patterns indicated that the films grown on the maskless patterned Si substrates were mainly composed of crystal planes with (111) orientation

Investigation on Step-Bunched Homoepitaxial Layers Grown on On-Axis 4H-SiC Substrates via Molten KOH Etching

Wafer-scale on-axis 4H-SiC epitaxial layers with very low roughness were obtained in this study. By performing carbon-rich hydrogen etching and epitaxial growth of the epitaxial layer at different temperatures, local mirror regions (LMRs) with root mean square (RMS) roughness less than 0.2 nm were obtained on the epitaxial layer surface. The LMRs’ length is tens of millimeters, and the width is sub-millimeters. The step-flow growth induced by threading screw dislocations (TSDs) was observed on the epitaxial layer surface by atomic force microscopy (AFM), together with the double bi-atomic step-flow growth induced by the step bunch, which was the cause of LMRs. Furthermore, the growth mechanism was investigated by wet etching. The etching pits were found to be associated with 3C-SiC and their effect on the growth rate of epitaxial layers was further explored