Tracking the Turn Maneuvering Target Using the Multi-Target Bayes Filter with an Adaptive Estimation of Turn Rate.

Tracking the target that maneuvers at a variable turn rate is a challenging problem. The traditional solution for this problem is the use of the switching multiple models technique, which includes several dynamic models with different turn rates for matching the motion mode of the target at each point in time. However, the actual motion mode of a target at any time may be different from all of the dynamic models, because these models are usually limited. To address this problem, we establish a formula for estimating the turn rate of a maneuvering target. By applying the estimation method of the turn rate to the multi-target Bayes (MB) filter, we develop a MB filter with an adaptive estimation of the turn rate, in order to track multiple maneuvering targets. Simulation results indicate that the MB filter with an adaptive estimation of the turn rate, is better than the existing filter at tracking the target that maneuvers at a variable turn rate.

Auxiliary Truncated Unscented Kalman Filtering for Bearings-Only Maneuvering Target Tracking.

Novel auxiliary truncated unscented Kalman filtering (ATUKF) is proposed for bearings-only maneuvering target tracking in this paper. In the proposed algorithm, to deal with arbitrary changes in motion models, a modified prior probability density function (PDF) is derived based on some auxiliary target characteristics and current measurements. Then, the modified prior PDF is approximated as a Gaussian density by using the statistical linear regression (SLR) to estimate the mean and covariance. In order to track bearings-only maneuvering target, the posterior PDF is jointly estimated based on the prior probability density function and the modified prior probability density function, and a practical algorithm is developed. Finally, compared with other nonlinear filtering approaches, the experimental results of the proposed algorithm show a significant improvement for both the univariate nonstationary growth model (UNGM) case and bearings-only target tracking case.

Naphthomycins L-N, ansamycin antibiotics from Streptomyces sp. CS.

Previous analyses of the naphthomycin biosynthetic gene cluster and a comparison with known naphthomycin-type products from Streptomyces sp. CS have suggested that new products can be found from this strain. In this study, screening by LC-MS of Streptomyces sp. CS products formed under different culture conditions revealed several unknown peaks in the product spectra of extracts derived from oatmeal medium cultures. Three new naphthomycins, naphthomycins L (1), M (2), and N (3), and the known naphthomycins A (4), E (5), and D (6) were obtained. The structures were elucidated using spectroscopic data from 1D and 2D NMR and HRESIMS experiments.

A new azaphilone, kasanosin C, from an endophytic Talaromyces sp. T1BF.

The strain T1BF was isolated from the old bast tissue of Taxus yunnanensis and determined to be a member of Talaromyces. The extracts from the solid fermentation of Talaromycessp. T1BF were purified and obtained three azaphilones, including a new one. They were identified on the basis of spectral data as 6alpha-hydroxy-7beta-methyl-8-oxo-3-((E)- prop-1-en-1-yl)-5,6,7,8-tetrahydro-1H-isochromen-7-yl-4'-hydroxy-2'-methoxy-6'-methyl- benzoate, named as kasanosin C (1), entonaemin A (2) and (+)-mitorubrin (3).

[Prognostic Significance of Follicular Lymphoma International Prognostic Index 2 (FLIPI2) in Follicular Lymphoma Patients Treated with Rituximab Maintenance].

OBJECTIVE: To investigate the prognostic significance of Follicular Lymphoma International Prognostic Index 2 (FLIPI2) in FL patients treated with rituximab maintenance. METHODS: A tatol of 140 newly diagnosed FL patients who received Rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) chemotherapy in our department were retrospectively analyzed from December 2002 to December 2014. Among 140 patients with FL 122 patients achieved response, from them 56 patients received R maintenance (RM) every 2 months for median 8 times (RM group) while the rest 66 patients did not receive further anti-lymphoma treatment (non-RM group). RESULTS: There was no statistical difference in age, sex, pathologic grading, staging, FLIPI or FLIPI2 between RM and non-RM groups. The 2-year progression-free survival (PFS) of RM and non-RM groups were 89.7% and 77.6% (P=0.043) while the 2-year overall survival were 100% and 98.6% (P=0.131). FLIPI2 is a significant prognostic model either in the total cohort, RM or non-RM groups (P<0.001 all). In subgroup analysis, RM was able to decrease disease progression in low and intermediate-risk group of FLIPI2, while the 2-year PFS of RM and non-RM groups in high-risk group were similar (55.6% vs 46.9%)(P=0.920). CONCLUSION: FLIPI2 presents robust prognostic significance either in RM or OBS patients, the patients in FLIPI2 low and intermediate-risk group may benefite from RM, but the role of RM in high-risk patients should be further to investigate.

Catalytic Asymmetric Formal Total Synthesis of (-)-Triptophenolide and (+)-Triptolide.

Catalytic asymmetric formal synthesis of (-)-Triptophenolide and (+)-Triptolide have been achieved. Key reaction involves Palladium catalyzed asymmetric conjugate addition of aryl boronic acid to 3-methyl cyclohexe-1-none to form quaternary carbon. Claisen rearrangement and subsequent aldol reaction furnished trans-decaline key intermediate, which assured a formal total synthesis of (-)-Triptophenolide and (+)-Triptolide.

One-step semisynthesis method of spirocurcasone and pyracurcasone from curcusones A and B.

High contents of curcusones A and B and trace amounts of spirocurcasone exist in the roots of Jatropha curcas. Here, a one-step semisynthesis method of spirocurcasone and pyracurcasone was built, not only resulted an increased yield of spirocurcasone but also produced pyracurcasone, which exhibited greater cytotoxicity compared to curcusones A and B. The plausible mechanism of the formation of pyracurcasone was proposed, and the proposed biogenetic origin for spirocurcasone by Taglialatela-Scafati was confirmed.

Chukfuransins A-D, four new phragmalin limonoids with ß-furan ring involved in skeleton reconstruction from Chukrasia tabularis.

Four new phragmalin limonoids (chukfuransins A-D) were isolated from the twigs and leaves of Chukrasia tabularis. Chukfuransins A (1) and B (2) feature a unique C-15/C-20 linkage proposed to be built by a biogenetic pathway involving Michael addition. Chukfuransins C (3) and D (4) feature the C-15/C-21 linkage. Their structures and absolute configurations were established by NMR techniques and X-ray crystallographic analysis.