A new elite opposite sparrow search algorithm-based optimized LightGBM approach for fault diagnosis.

In this paper, a new fault diagnosis approach based on elite opposite sparrow search algorithm (EOSSA) optimized LightGBM is proposed. It is necessary to extract appropriate features when dealing with high-dimensional data. Since the distribution of the high-dimensional data is not always approximately subject to a normal distribution, it will cause errors when it is approximated to normal distribution for feature extraction. The dimension reduction algorithms based on Euclidean distance often ignore the change of data distribution. To address this problem, cam locally linear discriminate embedding (CLLDE) based on cam weighted distance is proposed, which can improve the performance dealing with the deformed data of locally linear discriminate embedding (LLDE). The performance of CLLDE is better than LLDE on the iris dataset. It is important to establish a classifier with optimized hyper-parameters for fault identification. Sparrow search algorithm (SSA) is a novel optimization algorithm, which has achieved good results in many applications, but its optimization ability and convergence speed still need to be improved. Elite opposite sparrow search algorithm (EOSSA) is proposed by introducing elite opposite learning strategy and orifice imaging opposite learning strategy into SSA. The optimization results on benchmark functions show that EOSSA converges faster and has better optimization ability compared with the other five algorithms. EOSSA is used to optimize the hyper-parameters of LightGBM to train a classifier that can obtain a better fault recognition rate. Finally, the effectiveness of the proposed fault diagnosis approach is verified on Tennessee Eastman (TE) process dataset. Experiment results demonstrate that the EOSSA-LightGBM-based approach is superior to other algorithms.

[Analysis of porphyrin photosensitizers using HPLC method].

Photodynamic therapy (PDT), because of its good targeting, minimal invasion, and safety, is becoming a very active area in cancer prevention and treatment, in which the photosensitizers have proved to be the core element for PDT. We developed a new HPLC method for analyzing porphyrin photosensitizers using Shiseido Capcell PAK C18 (150 mm x 4.6 mm, 5 µm) as the column at 30 °C, methanol-1% aqueous solution of acetic acid as the mobile phase in a flow rate of 1.0 mL · min(-1) in a gradient elution mode, and the detection wavelength at 380 nm. This method, showing good specificity, precision, accuracy and robusty via methodology validations, can be applied to the purity test and assay of porphyrin photosensitizers, and has played a key guide role in the R&D of the new porphyrin photosensitizer--sinoporphyrin sodium.

Boswellic acid acetate induces apoptosis through caspase-mediated pathways in myeloid leukemia cells.

The mechanism of the cytotoxic effect of boswellic acid acetate, a 1:1 mixture of alpha-boswellic acid acetate and beta-boswellic acid acetate, isolated from Boswellia carterri Birdw on myeloid leukemia cells was investigated in six human myeloid leukemia cell lines (NB4, SKNO-1, K562, U937, ML-1, and HL-60 cells). Morphologic and DNA fragmentation assays indicated that the cytotoxic effect of boswellic acid acetate was mediated by induction of apoptosis. More than 50% of the cells underwent apoptosis after treatment with 20 mug/mL boswellic acid for 24 hours. This apoptotic process was p53 independent. The levels of apoptosis-related proteins Bcl-2, Bax, and Bcl-XL were not modulated by boswellic acid acetate. Boswellic acid acetate induced Bid cleavage and decreased mitochondrial membrane potential without production of hydrogen peroxide. A general caspase inhibitor (Z-VAD-FMK) and a specific caspase-8 inhibitor II (Z-IETD-FMK) blocked boswellic acid acetate-induced apoptosis. The mRNAs of death receptors 4 and 5 (DR4 and DR5) were induced in leukemia cells undergoing apoptosis after boswellic acid acetate treatment. These data taken together suggest that boswellic acid acetate induces myeloid leukemia cell apoptosis through activation of caspase-8 by induced expression of DR4 and DR5, and that the activated caspase-8 either directly activates caspase-3 by cleavage or indirectly by cleaving Bid, which in turn decreases mitochondria membrane potential.

Boswellic acid acetate induces differentiation and apoptosis in highly metastatic melanoma and fibrosarcoma cells.

The aim of the study was to investigate the antitumor and/or preventive effect of BC-4, an isomeric compound isolated from the plant Boswellia carteri Birdw. containing alpha- and beta-boswellic acid acetate in 1:1, MW 498.3. We used the MTT (3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide) assay to study the growth inhibition activity of BC-4. Tumor cells migration within a three-dimensional collagen matrix was recorded by time-lapse videomicroscopy and computer-assisted cell tracking. Topoisomerase II was isolated from mouse melanoma B16F10 cells and its activity was determined by its ability to cut plasmid pBR322 DNA. The secretion and activity of matrix metalloproteinases (MMPs) from human fibrosarcoma HT-1080 cells were determined by gelatin zymography. BC-4 was a cytostatic compound and could induce the differentiation of B16F10 mouse melanoma cells, blocked the cell population in G1 phase and inhibited topoisomerase II activity. The G1 phase population of B16F10 cells was increased from 57.4 to 87.7%, while S phase population was reduced from 33.3 to 5.9% after treatment with BC-4 at 25 microM concentration for 48 h. BC-4 also inhibited the migration activity of B16F10. BC-4 could induce apoptosis of HT-1080 cells, as proved by acridine orange fluorescence staining, Wright-Giemsa staining, electromicroscopy, DNA fragmentation and flow cytometry. BC-4 inhibited the secretion of MMPs from HT-1080 cells, too. In conclusion, if it turns out that BC-4 is a well tolerated substance, exhibiting no significant toxicity or side effects, being evaluated currently in China, BC-4 is a good candidate for the prevention of primary tumor, invasion and metastasis.

Regio- and stereoselective hydroxylation of taxoids by filamentous fungi.

Paclitaxel (Taxol), is one of the most promising chemotherapeutic agents developed for cancer treatment in past two decades. Microorganisms such as filamentous fungi are known to perform regio- and stereoselective hydroxylation of taxoids. Herein, we describe highly regio- and stereoselective hydroxylation at the 1beta and 9alpha positions of the taxane skeleton. Such hydroxylation reactions proceed readily for the taxadienes as substrates rather than taxoids having an oxetane ring. The presence of different oxygen substituents on the taxane nucleus, such as 5-acetoxy, has a significant effect on the selectivity and yield of the hydroxylation catalyzed by the microbial oxidases.

Synthesis and cytotoxicity of 2alpha-amido docetaxel analogues.

Various 2-amido docetaxel analogues were prepared and evaluated for their cytotoxicities. Among them, m-methoxy and m-chlorobenzoylamido analogues were most active but not superior to docetaxel and paclitaxel, and D-seco analogues inactive. Change of 2-benzoate to 2-benzamide may not improve their activities to drug-resistant cell lines.