Thermal Behavior Analysis of Two Synthesized Flavor Precursors of N‐alkylpyrrole Derivatives

To expand the library of pyrrole‐containing flavor precursors, two new flavor precursors—methyl N‐benzyl‐2‐methyl‐5‐formylpyrrole‐3‐carboxylate (NBMF) and methyl N‐butyl‐2‐methyl‐5‐formylpyrrole‐3‐carboxylate (NUMF)—were synthesized by cyclization, oxidation, and alkylation reactions. Thermogravimetry (TG), differential scanning calorimeter, and pyrolysis–gas chromatography/mass spectrometry were utilized to analyze the thermal degradation behavior and thermal degradation products of NBMF and NUMF. The TG‐DTG curve indicated that the maximum mass loss rates of NBMF and NUMF appear at 310 and 268°C, respectively. The largest peaks of NBMF and NUMF showed by the differential scanning calorimeter curve were 315 and 274°C, respectively. Pyrolysis–gas chromatography/mass spectrometry detected small molecule fragrance compounds appeared during thermal degradation, such as 2‐methylpyrrole, 1‐methylpyrrole‐2‐carboxylic acid methyl ester, limonene, and methyl formate. Finally, the thermal degradation mechanism of NBMF and NUMF was discussed, which provided a theoretical basis for their application in tobacco flavoring additives.     

A Dynamic Anomaly Detection Approach Based on Permutation Entropy for Predicting Aging-Related Failures

Software aging is a phenomenon referring to the performance degradation of a long-running software system. This phenomenon is an accumulative process during execution, which will gradually lead the system from a normal state to a failure-prone state. It is a crucial challenge for system reliability to predict the Aging-Related Failures (ARFs) accurately. In this paper, permutation entropy (PE) is modified to Multidimensional Multi-scale Permutation Entropy (MMPE) as a novel aging indicator to detect performance anomalies, since MMPE is sensitive to dynamic state changes. An experiment is set on the distributed database system Voldemort, and MMPE is calculated based on the collected performance metrics during execution. Finally, based on MMPE, a failure prediction model using the machine learning method to reveal the anomalies is presented, which can predict failures with high accuracy.     

Half‐sandwich Ruthenium (II) complexes with triphenylamine modified dipyridine skeleton and application in biology/luminescence imaging

Four half‐sandwich ruthenium^II (Ru^II) complexes with triphenylamine‐modifed dipyridine frameworks were synthesized and characterized. The cytotoxicity of target complexes toward A549 (lung cancer cells), HeLa (cervical cancer cells) and HepG2 (hepatoma cells) were obtained by the MTT assay, which were superior to cisplatin with the IC₅₀ values changed from 2.4 ± 0.1 μM to 9.2 ± 2.7 μM. Meanwhile, complexes possess the ability of antimetastasis to cancer cells. Ru^II complexes could be transported by serum albumin, catalyze the conversion of NADH (the reduced state of nicotinamide‐adenine dinucleotide) to NAD⁺ and induce the accumulation of reactive oxygen species, which confirmed the antineoplastic mechanism of oxidation. Ru^II complexes could enter A549 cells followed by a non‐energy dependent cellular uptake mechanism, target lysosomes with the Pearson's colocalization coefficient of 0.75, lead to lysosomal damage, disturb the cell cycle (S phase), and eventually induce apoptosis. The results demonstrate that these Ru^II complexes are potential anticancer agents with dual functions, including metastasis inhibition and lysosomal damage.     

The Linear Optical Unambiguous Discrimination of Hyperentangled Bell States Assisted by Time Bin

A linear optical unambiguous discrimination of hyperentangled Bell states is proposed for two‐photon systems entangled in both the polarization and momentum degrees of freedom (DOFs) assisted by time bin. This unambiguous discrimination scheme can completely identify 16 orthogonal hyperentangled Bell states using only linear optical elements, where the function of the auxiliary entangled Bell state is replaced by time bin. Moreover, the possibility of extending this scheme for distinguishing hyperentangled Bell states in n DOFs is discussed, and it shows that $2^{n+k+1}$ hyperentangled Bell states in n ( $n\ge 2$) DOFs can be distinguished with k ( $k<n$) auxiliary entangled states of additional DOFs by introducing a time delay, which decreases the auxiliary entanglement resource required for unambiguous discrimination of hyperentangled Bell state. Therefore, this scheme provides a new way for distinguishing hyperentangled states with current technology, which will extend the application of discrimination of hyperentangled states via linear optics to other quantum information protocols besides hyperdense coding schemes in the future.     

Novel stability condition for delayed fractional-order composite systems based on vector Lyapunov function

Nonlinear Dynamics - This paper proposes a novel stability condition for delayed fractional-order composite systems. First, we extend the vector Lyapunov function to the fractional-order systems to...     

Systematic chemical profiling of a multicomponent Chinese herbal formula Huo Luo Xiao Ling Dan by ultra high performance liquid chromatography coupled with electrospray ionization quadrupoletime‐of‐flight mass spectrometry

Huo Luo Xiao Ling Dan, a Chinese herbal formula consisting of 11 different herbs, has been used in folk medicine for the treatment of arthritis and other chronic inflammatory diseases. However, the chemical compositions of Huo Luo Xiao Ling Dan are not completely characterized. In the present study, an ultra high performance liquid chromatography coupled with electrospray ionization quadrupole time‐of‐flight mass spectrometry method in positive and negative ion modes was employed to identify biochemical constitutes in Huo Luo Xiao Ling Dan. As a result, a total of 76 compounds including alkaloids, monoterpene glycosides, iridoids, phenolic acids, and tanshinones, coumarins, lactones, flavones, and their glycosides, triterpenes, and triterpene saponins were characterized by comparing the retention time and mass spectrometry data with reference standards within 5 ppm error or by reference to the reference literature. These results would provide the basis for a further in vivo study of Huo Luo Xiao Ling Dan and information for potential new drug candidates for treating arthritis and other chronic inflammatory diseases.