Development of a 3-PRR Precision Tracking System with Full Closed-Loop Measurement and Control.

A 3-PRR (three links with each link consisting of a prismatic pair and two rotating pairs) parallel platform was designed for application in a vacuum environment. To meet the requirement of high tracking accuracy of the 3-PRR parallel platform, a full closed-loop control precision tracking system with laser displacement sensors and linear grating encoders was analysed and implemented. Equally-spaced laser displacement sensors and linear grating encoders were adopted not only for measurement but also for feedback control. A feed-forward control method was applied for comparison before conducting the closed-loop feedback control experiments. The closed-loop control experiments were conducted by adopting the PI (proportion and integration) feedback control and RBF (radial basis function) neural network control algorithms. The experimental results demonstrate that the feed-forward control, PI feedback control, and RBF neural-network control algorithms all have a better control effect than that of semi-closed-loop control, which proves the validity of the designed full closed-loop control system based on the combination of laser displacement sensors and linear grating encoders.

Kuguacins F-S, cucurbitane triterpenoids from Momordica charantia.

Chemical investigation of the vines and leaves of Momordica charantia resulted in isolation of fourteen cucurbitane triterpenoids, kuguacins F-S (1-14), including two pentanorcucurbitacins (6 and 7), one octanorcucurbitacin (8), and two trinorcucurbitacins (11 and 12), along with six known analogues. Their structures were elucidated on the basis of extensive spectroscopic and single-crystal X-ray diffraction analyses. Compounds 1-14 exhibited weak anti-HIV-1 activities in vitro.

Cytotoxic triterpenoid alkaloids from Buxus microphylla.

Five new triterpenoid alkaloids, buxmicrophyllines E-I (1-5), and six known ones (6-11) were isolated from the leaves and stems of Buxus microphylla. The structures of compounds 1-5 were elucidated by NMR and MS spectroscopic analysis, and the relative stereochemistry of 5 was determined by single-crystal X-ray crystallography. Compounds 3 and 9 were cytotoxic against HepG2 cells, with IC(50) values of 0.89 and 0.78 microM, and compounds 2, 3, 7, 8, and 9 were cytotoxic against K562 cells, with IC(50) values of 2.95, 4.44, 1.70, 5.61, and 0.37 microM, respectively.

A randomized controlled trial of ultrasound-guided pulsed radiofrequency for patients with frozen shoulder.

BACKGROUND: This study assessed the effectiveness and safety of ultrasound-guided pulsed radiofrequency (UGPRF) for patients with frozen shoulder (FS). METHODS: This study was designed as a randomized, double-blind, sham control trial. A total of 136 patients with FS were recruited and then were equally randomly allocated into a treatment group (n = 68) and a sham group (n = 68). The patients in the treatment group received UGPRF, while the subjects in the sham group underwent sham UGPRF. Patients in both groups were treated for a total of 12 weeks. The primary outcome was the pain intensity, measured by the visual analog scale (VAS). The secondary outcomes consisted of shoulder disorder, measured by the score of shoulder pain and disability index (SPADI); quality of life, assessed by the Short Form-36 questionnaire (SF-36); and any adverse events (AEs) during the treatment period. All outcomes were measured at baseline, at the end of 6-week, and 12-week treatment. RESULTS: At the end of 6 weeks, and 12 weeks, UGPRF showed more promising outcome results in pain relief, as measured by VAS (P <.01), improvement of shoulder disorder, as assessed by SPADI score (pain, P <.01; disability, P <.01; total, P <.01), and enhancement of quality of life, as measured by the SF-36 scale (PCS, P <.01; MCS, P <.01), compared with sham UGPRF in this study. CONCLUSION: The findings of this study showed that UGPRF may benefit for patients with FS after 12 weeks treatment.

Two novel lanostane triterpenoids from Ganoderma sinense.

Two novel lanostane-type triterpenes, Ganolactone B and Ganoderiol A triacetate, were isolated from the fruiting bodies of G. sinense, together with six known compounds. The structures of the two new triterpenes were determined as 3beta,7beta- dihydroxy-11,15-dioxo-lanosta-8-en-24-->20 lactone (1) and 3beta,24,26-triacetoxy-5alpha-lanosta-7,9(11)-dien-25-ol (2), respectively, by chemical and spectroscopic means.

Improved Slow Light Capacity In Graphene-based Waveguide.

We have systematically investigated the wideband slow light in two-dimensional material graphene, revealing that graphene exhibits much larger slow light capability than other materials. The slow light performances including material dispersion, bandwidth, dynamic control ability, delay-bandwidth product, propagation loss, and group-velocity dispersion are studied, proving graphene exhibits significant advantages in these performances. A large delay-bandwidth product has been obtained in a simple yet functional grating waveguide with slow down factor c/v(g) at 163 and slow light bandwidth Δω at 94.4 nm centered at 10.38 µm, which is several orders of magnitude larger than previous results. Physical explanation of the enhanced slow light in graphene is given. Our results indicate graphene is an excellent platform for slow light applications, promoting various future slow light devices based on graphene.

Digital speckle pattern interferometric measurement of diffusion coefficients in hydrogels.

The technique of real-time digital speckle pattern interferometry is proposed to study diffusion of surfactants in hydrogel. The diffusion coefficient is simply and directly determined from the interferograms. An example of diffusion coefficient measurement of surfactant in agarose gel demonstrates the usefulness ofthe method. The results obtained are compared with the theoretical simulating values.

Cycloartane triterpenoids from the aerial parts of Cimicifuga foetida Linnaeus.

Cycloartane triterpenoids, 2',24-O-diacetylisodahurinol-3-O-α-L-arabinopyranoside, 24-O-acetylisodahurinol-3-O-α-L-arabinopyranoside, 12ß-hydroxy-25-anhydrocimigenol, cimigenol-12-one, 12ß-hydroxy-15-deoxycimigenol, 2'-O-acetyl-24-epi-cimigenol-3-O-α-L-arabinopyranoside, 2'-O-acetylcimigenol-3-O-ß-D-xylopyranoside, 25-anhydrocimigenol-3-O-α-L-arabinopyranoside, 2',23-O-diacetylshengmanol-3-O-α-L-arabinopyranoside, and 2',24-O-diacetyl-25-anhydrohydroshengmanol-3-O-α-L-arabinopyranoside, together with eight known compounds, were isolated from aerial parts of Cimicifuga foetida. Their structures were determined by application of spectroscopic analyses and chemical methods. Biological evaluation of the compounds against human HL-60, SMMC-7721, A549, SK-BR-3, and PANC-1 cell lines indicated that three of these compounds exhibited broad-spectrum and moderate cytotoxic activities, with IC50 values ranging from 6.20 to 22.74 µM. By comparing previous cytotoxic testing data and bioassay results from this study, preliminary structure-activity relationships of compounds with a c imigenol-skeleton can be proposed.

Pregnane alkaloids from Pachysandra axillaris.

Nine new pregnane alkaloids, pachysamines J-R (1-9), together with seven known ones, were isolated from Pachysandra axillaris. The chemical structures of the new alkaloids were elucidated by spectroscopic methods. All the compounds were evaluated for their inhibitory activities against HL-60, SMMC-7721, A-549, SK-BR-3, and PANC-1 cell lines. Compound 15 possessed moderate activities against A-549, SK-BR-3, and PANC-1 cells, with the IC(50) values of 11.17, 4.17, and 10.76 microM, respectively. Besides, compound 11 showed cytotoxicities against A-549 cell, with the IC(50) values as 24.94 microM.