Genotypic and Environmental Effects on the Volatile Chemotype of Valeriana jatamansi Jones

Valeriana jatamansi Jones is an aromatic medicinal herb and important alternative to V. officinalis, which is utilized for medicinal purposes in China and India and also as spices in India. Bioactive ingredients of V. jatamansi vary in different regions. However, no information is currently available on influence of genotype and environmental factors in the volatile compounds, especially when germplasms and planting locations need to be selected. Based on the results of SNP and volatile constituents from GC-MS analysis, this study found various genotypes and chemotypes of V. jatamansi for wild plants from seven regions in China and common-garden samples; correlations between genotype and chemotype were revealed for the plants. Two distinct populations (PX, FY) were distinguishable from five others (GJ, YL, SY, DD, DY) according to their genotypes and volatile profiles, the consistency of which was observed showing that genotype could significantly influence chemotype. Wild populations and common-garden samples were also separated in their volatile profiles, demonstrating that environmental factors strongly affected their chemotypes. Compounds contributing to the discrimination were identified as discriminatory compounds. This investigation has explored and provided essential information concerning the correlation between genotype and chemotype as well as environmental factors and chemotype of V. jatamansi in some regions of China. Feasible plantation and conservation strategies of V. jatamansi could be further explored based on these results

A New Strategy for Efficient Synthesis of Medium and Large Ring Lactones without High Dilution or Slow Addition

We have developed an efficient method for medium and large ring lactone synthesis by a conceptually different ring-expansion strategy. The design of an unprecedented ring conjunction mode of oxetene, combined with the appropriate choice of a Lewis acid promoter and an additive, constitutes the key components of the new process. Enabled by this new approach, the reaction does not require high dilution or slow addition

Fabrication of a corrosion resistant superhydrophobic surface on magnesium alloy substrate

Superhydrophobic surface was obtained on pretreated magnesium alloy substrates via Nano silver deposition and electroless Ni-P plating followed by stearic acid modification. The surface with hierarchical structure had a water contact angle of 157.8° and exhibited excellent superhydrophobicity. The surface morphology of the sample, the chemical compositions and wettability were characterized by scanning electron microscopy (SEM), XRD (X-ray diffraction), Fourier transformed infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and water contact angle measurement. The potential polarization curves revealed the corrosion resistance of superhydrophobic sample was enhanced as the corrosion current density decreased by 2 orders of magnitude

Classification of Geological Samples Based on Soft Independent Modeling of Class Analogy Using Laser-Induced Breakdown Spectroscopy

Laser-induced breakdown spectroscopy with soft independent modeling of class analogy is used in the identification of a large number of unprocessed geological samples having similar components in this study. Considering a variety of data from different samples, representative spectral regions representing the major components were extracted. In addition, principal component analysis was applied to remove noninformative variables from the spectrum. The unclassification rate, misclassification rate, and average correct classification rate for 25 types of geological samples were 1.2%, 4.7%, and 94.1%, respectively. These results suggest that laser-induced breakdown spectroscopy using soft independent modeling of class analogy can be used to identify a wide variety of geological samples. Furthermore, we found that this approach can be used to identify spectral differences among similar sample types because of matrix effects and the trace element impurities

A New Strategy for Efficient Synthesis of Medium and Large Ring Lactones without High Dilution or Slow Addition

We have developed an efficient method for medium and large ring lactone synthesis by a conceptually different ring-expansion strategy. The design of an unprecedented ring conjunction mode of oxetene, combined with the appropriate choice of a Lewis acid promoter and an additive, constitutes the key components of the new process. Enabled by this new approach, the reaction does not require high dilution or slow addition

A New Strategy for Efficient Synthesis of Medium and Large Ring Lactones without High Dilution or Slow Addition

We have developed an efficient method for medium and large ring lactone synthesis by a conceptually different ring-expansion strategy. The design of an unprecedented ring conjunction mode of oxetene, combined with the appropriate choice of a Lewis acid promoter and an additive, constitutes the key components of the new process. Enabled by this new approach, the reaction does not require high dilution or slow addition

Magnetic and levitation characteristics of bulk high-temperature superconducting magnets above a permanent magnet guideway

Due to the large levitation force or the large guidance force of bulk high-temperature superconducting magnets (BHTSMs) above a permanent magnet guideway (PMG), it is reasonable to employ pre-magnetized BHTSMs to replace applied-magnetic-field-cooled superconductors in a maglev system. There are two combination modes between the BHTSM and the PMG, distinguished by the different directions of the magnetization. One is the S-S pole mode, and the other is the S-N pole mode combined with a unimodal PMG segment. A multi-point magnetic field measurement platform was employed to acquire the magnetic field signals of the BHTSM surface in real time during the pre-magnetization process and the re-magnetization process. Subsequently, three experimental aspects of levitation, including the vertical movement due to the levitation force, the lateral movement due to the guidance force, and the force relaxation with time, were explored above the PMG segment. Moreover, finite element modeling by COMSOL Multiphysics has been performed to simulate the different induced currents and the potentially different temperature rises with different modes inside the BHTSM. It was found that the S-S pole mode produced higher induced current density and a higher temperature rise inside the BHTSM, which might escalate its lateral instability above the PMG. The S-N pole mode exhibits the opposite characteristics. In general, this work is instructive for understanding and connecting the magnetic flux, the inner current density, the levitation behavior, and the temperature rise of BHTSMs employed in a maglev system