A new secondary metabolite from the fermented mycelia of Streptomyces antibiotic H41-55.

An actinomycete strain, H41-55 from sea sediment was identified as Streptomyces antibiotic on the basis of its morphological, physiological and biochemical characteristics as well as 16S rDNA data. A new secondary metabolite, (2S,3R)-N-[3-(formylamino)-2-hydroxybenzoyl]-l-threonine propyl ester (1), together with five known compounds was isolated from fermentation product by use of silica gel and Sephadex LH-20 column chromatography, and preparative RP-C18 HPLC, and identified by HR-TOF-MS and NMR spectra. The cytotoxicities of these isolates against three cancer cell lines and their antifungal activities on Candida albicans were tested. Compounds 1, 3, 5, and 6 displayed moderate cytotoxicity. 5 and 6 showed inhibitory activity on C. albicans.

[Research on ground scenery spectral radiation source with tunable spectra].

A spectrum-tunable ground scenery spectrum radiation source, using LEDs and bromine tungsten lamp as luminescence media, was introduced. System structure and control of the spectrum radiation source was expounded in detail. In order to simulate various ground scenery spectrum distribution with different shapes, a ground scenery spectral database was established in the control system. An improved genetic algorithm was proposed, and a large number of ground scenery spectra were produced by the simulator. Spectral similarity and the average spectral matching error of several typical ground scenery spectra were further analyzed. Spectral similarity of red bands, green bands, blue bands and near-infrared spectral band also was discussed. When the radiance of the target was 50 W x (m2 x sr)(-1), the average spectral matching error was less than 10% and spectral similarity was greater than 0.9, up to 0.983. Spectral similarity of red band, green band, blue band and near-infrared band (especially green band and near-infrared band) was less than that of full-band. Compared with blue band and red band, spectral similarity of green band and near-infrared band low-amplitude maximum can rearch 50%. Ground scenery spectrum radiation source can be used as radiometric calibration source for optical remote sensor, and calibration error, which is caused by objectives and calibration sources spectral mismatch, can be effectively reduced.

[Effectiveness and safety of acupuncture for supraventricular tachycardia: a systematic review and meta-analysis].

The effectiveness and safety of acupuncture for the treatment of supraventricular tachycardia were systematically reviewed. The randomized controlled trials (RCTs) regarding acupuncture for supraventricular tachycardia were searched in domestic and overseas databases, and the evaluation tool of bias risk in Cochrane Handbook 5.1.0 software was used to perform the evaluation of bias risk in literature, and RevMan 5.2 software was applied for statistics and Meta-analysis. Five RCTs involving 323 patients were included. The results showed that compared with the blank control group, the acupuncture reduced the heart rate by 18.8 times/min [95% CI (12.68, 24.92)]; the clinical effective rate in the acupuncture group was superior to that in the diltiazem group [OR= 3.11, 95% CI (1.50, 6.46)]; the difference of immediate effect between propafenone and acupuncture was not significant. No reports regarding adverse events was described in 5 RCTs. As was shown in the present evidence, acupuncture is safe and effective for the treatment of supraventricular tachycardia, but the level of evidence was low and the intensity of conclusion needed to be improved.

[Spectral calibration for the large aperture infrared radiometer].

The present paper introduced a spectral calibration method to calibrate a large aperture infrared radiation facility. We developed a radiometer which consisted of optical system, infrared detectors(cavity pyroelectric detector and HgCdTe detector 2 - 14 microm), fine mechanical modulator, lock in amplifier, signal processor, etc. At first, we analyzed the method on how to measure the spectral calibration of the large aperture infrared radiometer, and established the spectral calibration facility. Then, we tested the nonlinear response for the cavity pyroelectric detector and HgCdTe detector. Finally, we used the cavity pyroelectric detector to calibrate the relative spectral responsivity of HgCdTe detector at several wavelengths on the facility. Through the comparison of the two methods for measuring the relative spectral responsivity, the average of multiple measurements and comparative analysis of two methods were given. The uncertainty analysis of the whole system showed that the measurement uncertainty of the facility was better than 3.4%.

Study on effect of danshensu in directional differentiation of mesenchymal stem cells into neuron-like cells / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To study the effect of Danshensu (DSS) on directional differentiation of mesenchymal stem cells (MSC) into neuron-like cells.</p><p><b>METHODS</b>MSC were separated from bone marrow with density gradient centrifugation, wall sticking screening and amplified in vitro. Flow cytometry was used to monitor the expression of surface antigens. DSS contained in non-serum L-DMEM was used to induce differentiation of MSC to neuronlike cells, and the effect of DSS when different concentration and acting time used was explored. And levels of neuron-specific enolase (NSE), neurofilament protein (NF-M), nestin, and expression of glial fibrillary acidic protein (GFAP) were measured by immunohistochemical method.</p><p><b>RESULTS</b>After being propagated and amplified in vitro, MSC were positively expressed for CD29, CD44, CD166, and negatively expressed for CD14, CD34, CD45, HLA-DR. After induction of DSS, MSC exhibited the typical form of perikaryon with pyknotic cell body and prominence projected like that of neuron. These cells were positively expressed in NSE, NF-M and nestin, and negatively expressed in GFAP.</p><p><b>CONCLUSION</b>DSS could induce differentiation of MSC to neuron-like cells in vitro, the action is concentration- and time-dependent.</p>